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

ofstream fo("fact.out");
ifstream fi("fact.in");
int p;
long long fact=1,cinci,doi;

int main()
{
    fi>>p;


    while(1<2)
    {
        int copie=fact;

        while(copie%5==0)
        {
            cinci++;
            copie/=5;
        }

        while(copie%2==0)
        {
            doi++;
            copie/=2;
        }

        if(doi==p || cinci==p)
        {
            fo<<fact;
            break;

        }

        fact++;
    }


    return 0;
}