import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int X = scan.nextInt();
		int l = 100001;
		long []a = new long[l];

		for(int i = 0; i < N; i++) {
			a[scan.nextInt()] ++;
		}
		scan.close();
		long ans = 0;
		for(int i = 0; i < l; i++) {
			int res = X - i;
			if(res >= 0 && res <= 100000) {
				ans += a[i] * a[res];
			}
		}
		System.out.println(ans);
	}
}