#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    int p,i=1,ok=0;long long nr=1,prod=1;
    ifstream fin("fact.in");
    ofstream fout("fact.out");
    fin>>p;
    if(p<=8)
    {
         while(p)
        {
            nr*=10;
            p--;
        }
        while (ok==0)
        {
            prod*=i;
            i++;
            if(prod%nr==0) ok=1;
        }
        fout<<i-1;
    }
   else fout<<"-1";
    return 0;
}