#include <iostream>
#include <fstream>
#include <string>

using namespace std;
ifstream fin("fact.in");
ofstream fout("fact.out");
int nrZerouri(long long int a) {
	int sum = 0;
	while (a != 0) {
		int rest = a % 10;
		if (rest == 0) sum++; else
			break;
		a /= 10;
	}
	return sum;
}
long long int fact(int n) {
	if (n >= 1) { return n * fact(n - 1); }
	else { return 1; }
}


int main()
{
	int a;
	fin>> a;
	int valori[1000];
	if (a == 0)fout << 1; else
	{
		int s = 5;
		for (int i = 1; i <= 100; i++) {
			valori[i] = s;
			s += 5;
		}
	}
	fout << valori[a];
	fin.close();
	fout.close();
	return 0;
	
}