import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		sc.close();

		long s = (long) n * (n + 1) / 2;
		if (s <= m) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	}
}