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

s = set()
for a in A:
    s.add(a%m)
ans = 0

if m%2:
    print(0)
    exit()

for a in A:
    na = (a+m//2)%m
    if na in s:
        ans += n-2
print(ans//2)