#include<bits/stdc++.h>
using namespace std;
using ll=long long;



int main(){
  ll n;
  cin >> n;
  ll ans=n/25;
  n=n%25;
  if(n!=0)ans+=n/10;
  n=n%10;
  if(n!=0)ans+=n/5;
  n=n%5;
  ans+=n;
  cout << ans << endl;
  return 0;
}

