class Solution {
public:
    /*
     * @param n: A long integer
     * @return: An integer, denote the number of trailing zeros in n!
     */
    long long trailingZeros(long long n) {
        // write your code here, try to do it without arithmetic operators.
        long long sum=0;
        while(n>5)
        {
            sum+=n/5;
            n=n/5;
        }
        return sum;
    }
};