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