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

int main()
{
    ifstream fin("fact.in");
    ofstream fout("fact.out");
    int p;
    long long n=5,n1;
    fin>>p;
    if (p==0) fout<<'1';
    else
    {
        while (p>0)
        {
            n1=n;
            for (;n1%5==0;n1/=5,p--) {}
            n+=5;
        }
        n-=5;
        fout<<n;
    }
    return 0;
}