#include<fstream>
using namespace std;

int main()
{
	long long p,r,z;
	ifstream in("fact.in");
	ofstream out("fact.out");
	in>>p;
	r=1;
	z=0;
	if(z<p)
	r=0;
	while(z<p)
	{
		r+=5;
		z++;
	}
	out<<r;
	in.close();
	out.close();
	return 0;
}