public class Test05 {
	public static void main(String[] args) {
		int q, m;
		int p = 0, h = 0;
		do
		{
			p++;
			q = 78 - p;
			m = q * p;
			h += m;
		} while (p < 77);
		System.out.printf("%d", h);
	}
}
