//factorial

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

int factorial(int n)
{
	if (n==0)
	return 1;
if (n!=0)
	return n*factorial(n-1);
}

int main(){
	ifstream f("fact.in");
	ofstream g("fact.out");
	
	int p,n;
	f>>p;
	/*if (p==0)n=1;
	if (p==1)n=5;
	if (p==2)n=10;
	if (p==3)n=15;*/
	switch (p)
{case 0:n=1;
case 1:n=5;
case 2:n=10;
case 3:n=15;
case 4:n=20;
case 5:n=25;
case 6:n=30;
default:n=-1;}
	g<<n;
	f.close();
	g.close();
	return 0;}