#include<fstream>
#include<iostream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");
int P,cifre,N=5,k;

int main()
{
    f>>P;
    if (P==0) g<<1;
    else if (P>1)
    {
        while (cifre<P)
        {
            k=5;
            while (true)
            {
                if (N%k==0)
                    cifre++;
                else
                    break;
                k*=5;
            }
            N+=5;
        }
        g<<N-5;
    }
    else g<<-1;
    f.close();g.close();
    return 0;
}