def solve(lines):
    _, X = int(lines[0].split(" ")[0]), int(lines[0].split(" ")[1])
    a = [int(a) for a in lines[1].split(" ")]
    comps = set()
    count = 0
    for ai in a:
        comps.add(X - ai)

    for ai in a:
        if ai in comps:
            count += 1

    return count

if __name__ == "__main__":
    print(solve([input(), input()]))