import sys
sys.setrecursionlimit(5*10**5)
input = sys.stdin.readline
from collections import defaultdict, deque, Counter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right
from math import gcd

n,m = map(int,input().split())
a = list(map(int,input().split()))

s = set()
ans = 0
for i in range(n):
    op = (a[i]+(m//2)) % m
    if op in s:
        ans += n-2
    s.add(a[i])
print(ans*(m%2==0))