def ip():return int(input())
def mp():return map(int, input().split())
def lmp():return list(map(int, input().split()))
N, M = mp()
A = lmp()
if M % 2 == 1:
    exit(print(0))
from collections import defaultdict
cnt = defaultdict(int)
for i in range(N):
    cnt[A[i]] = i+1
    cnt[A[i]+M] = N+i+1
from itertools import accumulate
A.sort()
cum = [0] + list(accumulate(A+A))
ans = 0
from bisect import bisect_left
M2 = M//2
for a in A:
    if cnt[a+M2]:
        ans += cnt[a+M2] - cnt[a] - 1
        # print(a, ans)
print(ans)