CSES – Trailing Zeros

#include<bits/stdc++.h>
#define int long long
#define double long double
#define f first
#define s second
#define fastio ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
//declare
int n;
//
signed main(){
    fastio;
    cin>>n;
    int ans=0;
    while(n >= 5){
        n /= 5;
        ans += n;
    }
    cout<<ans<<"\n";
    return 0;
}