import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scan = new Scanner(System.in); int n = scan.nextInt(); double a = scan.nextDouble(); double sum = 0; for(int i = 0; i < n; i++) { sum += scan.nextDouble(); } scan.close(); double m = sum / n; System.out.println(m - a); if(m == a) { System.out.println("YES"); }else { System.out.println("NO"); } } }