Suleiman's Camels

" My name is Suleiman. My father, Abdullah had 13 sons including me. We had a lot of camels. At the death bed Abdullah wrote the will regarding the partition of camels among us. It had a strange nature. We are supposed to go to his best friend, Mr Ahmed, after his death and seek his help with the will. Ahmed was a wise man.

The will instructs Ahmed to add one of his camels to my father's camels and ask each of us (sons of Abdullah) to choose any count. By count he meant a natural number. If the number is 'N' the son will get 'Nth' of the total camels. But after the partition there can be only one camel left which Ahmed may take back. If the numbers we chose fails to satisfy this condition all of the camels goes to Ahmed.

The eldest sons Salam and Salim chose the numbers very carefully so that they got the maximum possible share. Sum of their share is 'X' camels. I am the 3rd son. what is the maximum number of camels that I can get? "

PS: To be clear, assume Abdullah had 99 camels. Then adding Ahmed's camel the total will be 100. If a son chooses the count '25' then he will get 25th of the total camels, ie, $\frac{100}{25}$ = 4 camels.