INMO 2019 Discussion

This is the place where we may discuss various problems and get updates of INMO 19. I expect the students of different states to post some problems discussed in their INMOTC. I will regularly upload some problems and even practice tests for INMO and expect you to do so too. Hope we all do perform well in INMO and many of us may even get selected for INMO IN MY NEXT POST, I WILL SEND A MOCK TEST A BIT EASIER THAN INMO, AS IT IS JUST THE BEGINNING.

Note by Maalav Mehta
2 years, 5 months ago

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Comments

Inmo provisional scores are out!!

N Kansara - 2 years, 4 months ago

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What is your score? Mine is 16, Samip 19, Pritesh 29, tanishka 14 are the scores I know till now from GUJARAT

Maalav Mehta - 2 years, 4 months ago

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My scores look messed up. I could solve P1 and P2 and attempted P6 (almost pseudo proved it), but I got only 7. If there are 5 marks for attempting P6, then I was given only 2 marks for 2 correct questions. What the hell!

SRIJAN SHASHWAT - 2 years, 4 months ago

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@Srijan Shashwat P6 deserved to be deleted. Anyway, better to file RTI to get the truth about evaluation.

Suchir Kaustav - 2 years, 4 months ago

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@Suchir Kaustav I do agree. I made assumptions in P6 due to lack of options. Anyways, though I felt Functional Equations was my stronghold and I wasted a lot of time in that question, my best wishes to all who did really well. Hope India succeeds this time at IMO.

SRIJAN SHASHWAT - 2 years, 4 months ago

I am Param Kansara and I got 26 from Gujarat

N Kansara - 2 years, 4 months ago

Who is pritesh

N Kansara - 2 years, 4 months ago

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@N Kansara My friend from class 9. He studies at Allen

Maalav Mehta - 2 years, 4 months ago

Congrats, you got slected for INMO this year also. 23marks is impressive

Maalav Mehta - 1 year, 6 months ago

1st Indian National Mathematical Olympiad MOCK 2019 Time: 4 hours Instructions: • Calculators (in any form) and protractors are not allowed. • Rulers and compasses are allowed. • All questions carry equal marks. Maximum marks: 102.

1.A circle passes through the vertex C of a rectangle ABCD and touches its sides AB and AD at M and N respectively If the distance from C to the line segment MN is 5 units, find the area of ABCD.
2.Consider the set {3,5,7,9}. You can choose any 2 numbers a,b and replace them by (4a+3b)/5 and (3a-4b)/5. Prove that you can never get the set {2,3,4,9}.
3.A 3*3 square is said to be a mystic square if i)Its entries are from 1 to 13(both inclusive, repetition allowed) ii)The sum of any row, column or diagonal is always divisible by 13. Find the number of MYSTIC SQUARES.
4.In a triangle ABC, AB=AC and angle A is 20 degrees.D is chosen on AC such that AD=BC.Without using trigonometry, find angle ABD.
5.Let P(x) be a cubic polynomial function with positive coefficients..Prove, if -1≤P(x)≤1 for all x such that -1≤x≤1, prove that sum of coefficients of P(x) is at most 7.
6.Find all functions f:R to R which obey
f((x-y)²)=f(x)²-2xf(y)+f(y)²

Maalav Mehta - 2 years, 5 months ago

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Thanks for the mock test!!! What are you focusing on preparing??? Geometry??

Aaghaz Mahajan - 2 years, 5 months ago

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I want to improve at geometry, but I hate doing it.

Maalav Mehta - 2 years, 5 months ago

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@Maalav Mehta Well, you can start off with some problem solving on AOPS..........BUT, if u want to learn new stuff, the wikis on Brilliant are REALLY good ones...........

Aaghaz Mahajan - 2 years, 5 months ago

@Maalav Mehta Also, if u hate doing it, then focus on something which you like doing and prepare that.......:)

Aaghaz Mahajan - 2 years, 5 months ago

Which state are you from?

Maalav Mehta - 2 years, 5 months ago

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@Maalav Mehta I am from Noida..........(UP region).....You???

Aaghaz Mahajan - 2 years, 5 months ago

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@Aaghaz Mahajan Gujarat

Maalav Mehta - 2 years, 5 months ago

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@Maalav Mehta When is your INMOTC and which teachers are coming?

Maalav Mehta - 2 years, 5 months ago

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@Maalav Mehta WHOAH!!!! You have an INMOTC???!!! That is great dude.........yahan pe to aisa kuch inform nhi kara hai!! lol............

Aaghaz Mahajan - 2 years, 5 months ago

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@Aaghaz Mahajan You may ask your coordinator to arrange some camp or you may enquire in neighbouring states if they allow outside students

Maalav Mehta - 2 years, 5 months ago

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@Maalav Mehta All the best for tomorrow

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta Thanks!!!! Same to you!!

Aaghaz Mahajan - 2 years, 4 months ago

What about the last question in INMO 2019? Since the question was faulty, how will the marking be made?

Somaditya Santra - 2 years, 4 months ago

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Should simply be ignored and marks be awarded to none.

Suchir Kaustav - 2 years, 4 months ago

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But that is not correct as many would have spent hours on the problem as no one would have expected it to be incorrect. On the other hand, many wouldn't even have tried the question. It is unfair that both get 0 marks

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta i feel that someone who has tried to draw logical steps from the given statements in the problem should be awarded marks. Someone who forcibly tries to prove the false statement to be true must not be awarded marks. I really doubt if someone actually tied to disprove it.

Somaditya Santra - 2 years, 4 months ago

Let us post our scores Mine is 34

Amol Borade - 2 years, 4 months ago

my score is 54

Shirish Chinchanikar - 2 years, 4 months ago

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You will get selected for sure

Maalav Mehta - 2 years, 4 months ago

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but last to last year the cutoff was around 60

Shirish Chinchanikar - 2 years, 4 months ago

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@Shirish Chinchanikar But this time it is not so. Check out aops

Maalav Mehta - 2 years, 4 months ago

@Shirish Chinchanikar It was 47

Anubhav Mahapatra - 2 years, 3 months ago

Congratulations man!

SRIJAN SHASHWAT - 2 years, 4 months ago

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thanks!

Shirish Chinchanikar - 2 years, 4 months ago

Which region are you from?

Maalav Mehta - 2 years, 4 months ago

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maharashtra goa

Shirish Chinchanikar - 2 years, 4 months ago

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@Shirish Chinchanikar pune

Shirish Chinchanikar - 2 years, 4 months ago

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@Shirish Chinchanikar Were you merit holder, because in the lost I can't find someone from Maharashtra having 54 marks. There is one with 58 though

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta yes

Shirish Chinchanikar - 2 years, 4 months ago

@Maalav Mehta What is 'lost'

N Kansara - 2 years, 3 months ago

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@N Kansara sorry, I wanted to write list

Maalav Mehta - 2 years, 3 months ago

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@Maalav Mehta Which list?

N Kansara - 2 years, 3 months ago

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@N Kansara It is on aops

Maalav Mehta - 2 years, 3 months ago

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@Maalav Mehta But where?

N Kansara - 2 years, 3 months ago

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@N Kansara https://artofproblemsolving.com/community/c260h1781370 See the first post

Maalav Mehta - 2 years, 3 months ago

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@Maalav Mehta Thanks, what is your name in aops

N Kansara - 2 years, 3 months ago

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@N Kansara Math-Wiz

Maalav Mehta - 2 years, 3 months ago

Final scores are out. When do you expect the list will be revealed?

Madhur Agrawal - 2 years, 3 months ago

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What should be the merit cut off?

Suchir Kaustav - 2 years, 3 months ago

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I have no idea. 30-50 somewhere

Madhur Agrawal - 2 years, 3 months ago

40

Maalav Mehta - 2 years, 3 months ago

Find all functions f:R→R satisfying the equation f(f(x)) + f(x) = 6x

Maalav Mehta - 2 years, 5 months ago

ALL THE BEST FOR TOMORROW GUYS AND GIRLS!!!!!!!!!!!

Maalav Mehta - 2 years, 4 months ago

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Same to you!!!!

Aaghaz Mahajan - 2 years, 4 months ago

How did it go????? How many could you solve????

Aaghaz Mahajan - 2 years, 4 months ago

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None

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta Really?

Aryan Arya - 2 years, 4 months ago

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@Aryan Arya Yes

Maalav Mehta - 2 years, 4 months ago

@Aryan Arya What do you expect from a class 9 student?

Maalav Mehta - 2 years, 4 months ago

Do you think that the cut off may be lower this time since as per my experience this year, the paper was relatively tougher

Shubhraneel Pal - 2 years, 4 months ago

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Yes, the cutoff will be around 35-40

Maalav Mehta - 2 years, 4 months ago

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Greater than 42..check out AOPS

Anubhav Mahapatra - 2 years, 4 months ago

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@Anubhav Mahapatra What is your score? Any chances of selection?

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta No...I didn't do well...In Odisha highest score is 39 by Aatman...Most got single digit scores.however from the checking it is clear that if even a single step is wrong or a claim too you end up with a zero in that question

Anubhav Mahapatra - 2 years, 4 months ago

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@Anubhav Mahapatra Even in Gujarat the highest score is 29 as known till now(no idea about merit holders). So, no chances of selection in Gujarat

Maalav Mehta - 2 years, 4 months ago

Hey everyone. I appeared for INMO 2019 and solved P2 and P3. In P6, I managed to provide a "pseudo-proof" that f(x,y) =1. What are my chances of selection? Also, I couldn't solve P1 but I heard many saying that it was the easiest problem. Is this really the case?

Vibhav Aggarwal - 2 years, 4 months ago

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Hey dude........same case over here...........I mean even I have done the EXACT same things except P6, in which I was only able to prove the first part..........Oh well.......Chances are slim...........And Yes, P1 was the easiest......IDK why it did not strike me during the exam........!!!!

Aaghaz Mahajan - 2 years, 4 months ago

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Can you provide a hint for P1?

Vibhav Aggarwal - 2 years, 4 months ago

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@Vibhav Aggarwal Well, Allen has already posted their solutions, but my method was using a lot of trigonometry...........You know, Sine rule and Cosine rule........and that took me too long.....

Aaghaz Mahajan - 2 years, 4 months ago

Btw, which class are you in?? And from which state??

Aaghaz Mahajan - 2 years, 4 months ago

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I am in 12th class from Rajasthan state. What about you?

Vibhav Aggarwal - 2 years, 4 months ago

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@Vibhav Aggarwal Ohhh I am in class 11th.......Uttar Pradesh........

Aaghaz Mahajan - 2 years, 4 months ago

@Vibhav Aggarwal So, you are giving JEE???

Aaghaz Mahajan - 2 years, 4 months ago

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@Aaghaz Mahajan Yep

Vibhav Aggarwal - 2 years, 4 months ago

Did you hear that P6 was wrong? What would be impact. Will it be deleted or there could be a reexam??

Suchir Kaustav - 2 years, 4 months ago

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Check it on aops

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta What do u think? HBCSE will delete the qn?

Suchir Kaustav - 2 years, 4 months ago

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@Suchir Kaustav Probably, but that is not correct as many would have spent hours on the question without knowing that it is incorrect

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta What could be the cut off? I guess, it should be around 40-45.

Suchir Kaustav - 2 years, 4 months ago

HBCSE has provided an update on their site: "In question number 6 of the INMO2019 held on 20th January, 2019, a hypothesis was unfortunately left out inadvertently. As a result, the problem was incomplete. A suitable resolution of the problem will be worked out in consultation with examiners and students’ efforts will be taken care of during the evaluation. — B. Sury, National Co-ordinator."

Vibhav Aggarwal - 2 years, 4 months ago

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@Vibhav Aggarwal Yup........maybe they'll mark it correct for everyone and thus increasing the cutoff........

Aaghaz Mahajan - 2 years, 4 months ago

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@Aaghaz Mahajan No they probably won't do that. I think they will give 0 for no attempt and provide some marks according to the attempt.

Vibhav Aggarwal - 2 years, 4 months ago

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@Vibhav Aggarwal I don't think that would be reasonable. If marks for attempt is to be awarded then it should for every question and not just for question 6.

Suchir Kaustav - 2 years, 4 months ago

For p2 I did not use php but some approach that is explicitly not php but just the same thing as that. How much do I expect?

Shubhraneel Pal - 2 years, 4 months ago

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If it is mathematically correct, you get full

Maalav Mehta - 2 years, 4 months ago

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You don't have experience about change in checking methods

Anubhav Mahapatra - 2 years, 4 months ago

@Suchir Kaustav @Maalav Mehta Is this the first time this has happened that a question in inmo came wrong? If this did happen before then what was done? Any idea?

Shubhraneel Pal - 2 years, 4 months ago

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I remember it happened in 1999 and 2011. But no idea what was done

Maalav Mehta - 2 years, 4 months ago

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Reexam is a huge logistical challenge on the part of HBCSE. I think they should increase the number of selections.

Suchir Kaustav - 2 years, 4 months ago

Inmo 2019 cutoff

Akhil Dev - 2 years, 4 months ago

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Around 48

Maalav Mehta - 2 years, 4 months ago

Provisional cutoff ~50...may increase after re-evaluation...btw how many of u guys are expecting increase in ur score..plz post ur current score and expected score

Soutrik Sarangi - 2 years, 3 months ago

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where did you find provisional cutoff

Shirish Chinchanikar - 2 years, 3 months ago

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@Shirish Chinchanikar Aops

Soutrik Sarangi - 2 years, 3 months ago

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@Soutrik Sarangi What should be the merit cut off?

Suchir Kaustav - 2 years, 3 months ago

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@Suchir Kaustav 38

Maalav Mehta - 2 years, 3 months ago

What was the cut off then for IMOTC?

Madhur Agrawal - 2 years, 3 months ago

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Results declared. The cutoff is most probably 46

Maalav Mehta - 2 years, 3 months ago

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Cool cool.

Madhur Agrawal - 2 years, 3 months ago

What about Merit cut off? When will the merit list be declared?

Suchir Kaustav - 2 years, 3 months ago

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@Suchir Kaustav In August

Anubhav Mahapatra - 2 years, 3 months ago

good comment

Joseph Bush - 2 years, 1 month ago

https://brilliant.org/discussions/thread/inmo-2019-discussion/

Michael Jason - 2 years, 1 month ago

read about it on https://www.wikipedia.org/

Catherine Moss - 4 months, 1 week ago

How was the inmo?

Aman Pandey - 2 years, 4 months ago

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Tougher than ever, the fifth question used something called inversion(according to some AOPSers), which has not ever been asked in INMO. Could you solve P6?

Maalav Mehta - 2 years, 4 months ago

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Yeah problem no 6 looked easy but solving it took me complete hour and mind bending brainstorming and I skipped two or three lemmas and messed everything but solved it. Seems they would care to give 2 or 3 marks.

Aman Pandey - 2 years, 4 months ago

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@Aman Pandey How did you solve it?

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta No exotic methods just little brainstorming , some examples, inducing them ,predicting the power rule and then proved.😃

Aman Pandey - 2 years, 4 months ago

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@Aman Pandey Bro, the last question is incorrect and in the solution of Allen faculties, they have found a counter example

Maalav Mehta - 2 years, 4 months ago

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@Maalav Mehta Yes me too saw today my answer is as not Allen's solution buy I used the continuity of the function too. So seems wrong now.

Aman Pandey - 2 years, 4 months ago

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@Aman Pandey The power rule assumed by me was wrong as I thought only about rational numbers didn't seek for irrational ones.

Aman Pandey - 2 years, 4 months ago

If the ans is wrong and the approach is correct or vice versa how much can one expect??

Aryan Arya - 2 years, 4 months ago

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If the approach is more than 70 percent correct, you may expect 12 marks. If the answer is correct but obtained by doing some nonsensical stuff, then you may get 2 or 3 marks

Maalav Mehta - 2 years, 4 months ago

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If approach is more than 90% correct but you have even one fault then u get a zero

Anubhav Mahapatra - 2 years, 4 months ago

What's going on? When will results be posted? Final scores are out, that should be no trouble now

Madhur Agrawal - 2 years, 3 months ago

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Results will be out on 5 march

Maalav Mehta - 2 years, 3 months ago

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F

Madhur Agrawal - 2 years, 3 months ago

Hey what can be expected cutoff this year??

Aryan Arya - 2 years, 4 months ago

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RMO coordinator of Gujarat told that according to trend, you are required to solve 3-4 questions

Maalav Mehta - 2 years, 4 months ago

This time I guess cutoff will be around 40

Maalav Mehta - 2 years, 4 months ago

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What about cut off for merit certificate?

Suchir Kaustav - 2 years, 4 months ago

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@Suchir Kaustav about 25-35

minny bukhariya - 2 years, 4 months ago
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