Ionic Equilibrium - 1

What is the $\text{pH}$ of the resultant solution formed by adding these 5 weak acids?

Here $c$ is the Concentration and $k_a$ is the acid dissociation constant.

Acid 1 : ${c}_{1} = 0.1999 N$ , ${k}_{\text {a1}} = 2.036 × {10}^{-15}$

Acid 2 : ${c}_{2} = 0.02367 N$ , ${k}_{\text {a2}} = 5.0093× {10}^{-15}$

Acid 3 : ${c}_{3} = 0.5678 N$ , ${k}_{\text {a3}} = 3.9925 × {10}^{-16}$

Acid 4 : ${c}_{4} = 0.09826 N$ , ${k}_{\text {a4}} = 6.5762 × {10}^{-16}$

Acid 5 : ${c}_{5} = 6.753 N$ , ${k}_{\text {a5}} = 0.7036 × {10}^{-15}$

Enter your answer as $[ \text {pH} ]$ , where [ ] is greatest integer function.

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Original!

This is a part of my set Aniket's Chemistry Challenges . (BEST OF JEE - ADVANCED)