#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    ifstream f("fact.in");
    ofstream g("fact.out");

    int p,ct=0,aux;
    double n,i;
    f>>p;
    if(p==0)
        n=1;
    for(i=5;ct!=p;i+=5)
    {
        aux=i; n=i;
        while(aux%5==0)
        {
            ct++;aux/=5;
        }
    }
    g<<n;
    return 0;
}