127

#include<iostream>
using namespace std;
int main()
{
    int n,i,nrz=0,aux;
    cin>>n;
    for(i=5;i<=n;i=i+5)
     {
      aux=i;
       while(aux%5==0)
         {
          aux=aux/5;
          nrz++;
          }
    }
  cout<<nrz<<" ";
  }