N,X =map(int,input().split())
l =[0]*(10**5+1)
for i in input().split():
    s = int(i)
    l[s] += 1
ans = 0
if X < N:
    for i in range(X+1):
        ans += l[i]*l[X-i]
elif X <= 2*N:
    for i in range(X-N,N+1):
        ans += l[i]*l[X-i]
print(ans)