11! = 39916800, so the out should be 2

 1 class Solution {
 2     public long trailingZeros(long n) {
 3         long cnt = 0;
 4         while(n != 0){
 5             cnt += n / 5;
 6             n = n / 5;
 7         }
 8         return cnt;
 9     }
10 }