def mainProc(x, lst):
    lst.sort()

    ct = 0
    for i in lst :
        for j in lst :
            if i + j == x :
                ct += 1
            elif i + j > x :
                break
    print(ct)

if __name__ == '__main__':

    n, x = map(int,input().split())
    lst = [int(i) for i in input().split()]

    mainProc(x, lst)