import java.util.Scanner;

public class No_723 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		final int N = sc.nextInt();
		final int X = sc.nextInt();
		int count = 0;
		int mid = X / 2;
		int[] aa = new int[N];
		for (int i = 0; i < N; i++) {
			aa[i] = sc.nextInt();
		}

		for (int i = 0; i < N; i++) {
			for (int y = i + 1; y < N; y++) {
				if (aa[i] + aa[y] == X) {
					count++;
				}
			}


		}


		count *= 2;
		for (int i = 0; i < N; i++)
			if (mid == aa[i] && X % 2 == 0)
				count++;
		System.out.println(count);
	}
}