#include <iostream>
#include <fstream>
#include <math.h>

using namespace std;

ifstream fin("fact.in");
ofstream fout("fact.out");

int main() {
	int p;
	fin>>p;
	if(p<=4)
        fout<<5*p;
    if(p==5)
        fout<<"-1";
    if(p>5)
        fout<<5*(p-1);
	return 0;
}