N, X = map(int, input().split())
A = list(map(int, input().split()))
cnts = [0] * (max(A) + 1)
for i in range(N):
    cnts[A[i]] += 1
ans = 0
for i in range(max(A) + 1):
    d = X - i
    if 0 <= d <= max(A):
        ans += cnts[i] * cnts[d]
print(ans)