#include <iostream>
#include <fstream>

using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");

int main()
{
    int p,x,nr=0,cx;
    f>>p;
    x=5;
    if(p==0) g<<1;
    else
    {
        while(nr<p)
        {
            cx=x;
            while(cx%5==0)
            {
                cx=cx/5;
                nr++;
            }
            x=x+5;


        }
        if(nr==p)
            g<<x-5;
        else g<<-1;
    }
}