N, X = map(int, input().split())
A = list(map(int, input().split()))
from collections import defaultdict
dic = defaultdict(int)
for a in A:
    dic[a] += 1

if X > 2 * 10 ** 5:
    print(0)
    exit()
ans = 0
for i in range(X+1):
    ans += dic[i] * dic[X-i]

print(ans)