import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int target = sc.nextInt();
        HashMap<Integer, Long> count = new HashMap<>();
        while (n-- > 0) {
            int x = sc.nextInt();
            count.put(x, count.getOrDefault(x, 0L) + 1);
        }
        long ans = 0;
        for (int x : count.keySet()) {
            ans += count.get(x) * count.getOrDefault(target - x, 0L);
        }
        System.out.println(ans);
    }
}

class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}