The task is to generate the correct answer for a given math problem.

[EX Q]: Problem: find the least number must be subtracted from 62575 so that remaining number is divisible by 99 .
[EX A]: 7

[EX Q]: Problem: find the least number must be subtracted from 105829 so that remaining no . is divisible by 21 ?
[EX A]: 10

[EX Q]: Problem: a and b walk around a circular track . they start at 8 a . m from the same point in the opposite directions . a and b walk at a speed of 2 rounds per hour and 3 rounds per hour respectively . how many times shall they cross each other before 9 a . m
[EX A]:
5