number of trailing zeroes in Factorial of n

//Ex: There are 2 trailing zeroes in 10!

#include<stdio.h>

int main()
{
    long long n;
    scanf("%lld", &n);

    long long s = 0;
    while(n >= 5)
    {
        s += n / 5;
        n /= 5;
    }
    printf("%lld\n", s);
}