N,X = map(int, input().split())
A = [int(a) for a in input().split()]

M = max(A)+1
L = [0]*M
for a in A:
    L[a] += 1
ans = 0
for i in range(M):
    if X-i >= M or X-i < 0:
        continue
    ans += L[i]*L[X-i]
print(ans)