#!/usr/bin/env python3

import collections


def count_pairs(n, x, ys):
    ctr = collections.Counter(ys)
    res = sum(ctr[x - y] for y in ys)
    return res


def main():
    n, x = (int(z) for z in input().split())
    ys = [int(y) for y in input().split()]
    res = count_pairs(n, x, ys)
    print(res)


if __name__ == '__main__':
    main()