Can anyone explain me, what block size do I have to take, I thought its root(n), bt in this question https://www.codechef.com/problems/FCTRE (Factor Tree), when I took the size of block to be root(n), it gives TLE, when i further increase the size to 625 (constant), it still gives tle https://www.codechef.com/viewsolution/31965019 , bt when i increase it more to 1000, it gives an AC https://www.codechef.com/viewsolution/31965854 , why does that happen??, what block size do i have to take?