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