n, x = map(int, input().split())
a = list(map(int, input().split()))
cnt = {}
for i in a:
    if i in cnt:
        cnt[i] += 1
    else:
        cnt[i] = 1

ans = 0

for i in cnt:
    if x-i in cnt:
        ans += cnt[i]*cnt[x-i]

print(ans)