using System;
using static System.Console;

public class Hello{
    public static void Main(){
        string[] input = ReadLine().Split(' ');
        int kazu = int.Parse(input[0]);
        int total = int.Parse(input[1]);
        string[] number = ReadLine().Split(' ');
        int[] num = new int[110000];
        for(int i=0;i<kazu;i++){
            int a = int.Parse(number[i]);
            num[a]++;
        }
        
        int count = 0;
        for(int i=0;i<=total;i++){
            int j = total-i;
            if(i<=j){
                count += num[i] * num[j];
            }
        }
        WriteLine(count);
    }
}