import itertools
N, X = map(int, input().split())
A = list(map(int, input().split()))
_A = [A[i] for i in range(N) if not A[i] in A_]
__A = list(itertools.product(_A, repeat=2))
count = 0
for e in __A:
    if (e[0] + e[1]) == X:
        count += 1
print(count)