N, X = map(int, input().split())
A = list(map(int, input().split()))
D = {}
for i in A:
    if i in D:
        D[i] += 1
    else:
        D[i] = 1
S = 0
for i in A:
    if X - i in D:
        S += D[X-i]
print(S)