void main()
{
	const N = readInt;
	const M = readInt;
	auto A = new int[N];
	foreach (i; 0 .. N) {
		A[i] = readInt;
	}
	auto set = new RedBlackTree!(int, "a < b", false);
	foreach (i; 0 .. N) {
		set.insert(--A[i]);
	}
	long ans;
	foreach (i; 0 .. N) {
		if (((A[i] + M / 2) % M) in set) {
			ans += N - 2;
		}
	}
	ans /= 2;
	if (M % 2 == 1) ans = 0;
	writeln(ans);
}

import std,core.bitop;
string[]_R;
string readString(){while(_R.empty){_R=readln.chomp.split;}auto ret=_R.front;_R.popFront;return ret;}
int readInt(){return readString.to!int;}
long readLong(){return readString.to!long;}
ulong readULong(){return readString.to!ulong;}
real readReal(){return readString.to!real;}
bool chmin(T)(ref T A,T B){if(A>B){A=B;return true;}else{return false;}}
bool chmax(T)(ref T A,T B){if(A<B){A=B;return true;}else{return false;}}
int lowerBound(T)(T[]A,T x){int L=-1,R=cast(int)A.length;while(R-L>1){int mid=(L+R)/2;(A[mid]<x?L:R)=mid;}return R;}
int upperBound(T)(T[]A,T x){int L=-1,R=cast(int)A.length;while(R-L>1){int mid=(L+R)/2;(A[mid]<=x?L:R)=mid;}return R;}