#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");
int main()
{
    long long p, n, x, a;
    f>>p;
    n=5; x=0;
    if (p == 0) g<<1;
    else {
        while (x<p)
        {
            a=n;
            while (a/5 && a%5==0) { x++; a/=5; }
            if (x!=p) n=n+5;
        }
    if (x==p) g<<n;
    else g<<-1;
    }

    return 0;
}