using namespace std;
#include <iostream>
#include <stdio.h>
#include <fstream>

int main(){

    int n, copie, count = 0;

    freopen("fact.in","r",stdin);
    freopen("fact.out","w",stdout);
    cin >> n;

    for(int i = 5;;i+=5){
        copie = i;
        while(copie%5 == 0){
            count++;
            copie /= 5;
        }

        if(count == n){
            cout<<i;
            break;
        }
    }








    return 0;
}