n, x = map(int, input().split())
A = [int(input()) for _ in range(n)]
d = {}
ans = 0
for i in range(n):
    if A[i] in d:
        ans += d[A[i]]
    if A[i]^x in d:
        d[A[i]^x] += 1
    else:
        d[A[i]^x] = 1
print(ans)