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

int main()
{
    ifstream f("fact.in"); ofstream g("fact.out");
    int p; int i,j,x;
    f>>p;
    i=0;
    x=0;
    while ((x!=p) && (x<p))
    {
        i=i+5;
        j=i;
        while (j%5==0) {x++;j=j/5;}

    }
    if (x>p) {g<<-1; return 0;}
    if (x>0) g<<i; else g<<1;
    return 0;
}