#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("fact.in");
ofstream fout("fact.out");

int main()
{
    int p,ok=0;
    fin>>p;
    if(p!=0){fout<<1;ok=1;}
    else {fout<<5*p;ok=1;}
    if(ok==0)fout<<-1;
    return 0;
}