N, X = map(int,input().split())
A = list(map(int,input().split()))
cnt = [0 for _ in range(max(A)+1)]
ans = 0
for a in A:cnt[a] += 1
for a in A:
    if X-a >= 0 and X-a < len(cnt):
        ans += cnt[X-a]
print(ans)