#include<bits/stdc++.h>

#define INF 1000000007
#define LINF 1000000000000000007

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;


int n, x, a[100000], d[100001] = {0};

int main(){
	cin >> n >> x;
	for(int i = 0; i < n; i++){
		cin >> a[i];
		d[a[i]]++;
	}
	ll cnt = 0;
	if(x > 200000) cout << 0 << endl;
	else{
		for(int i = 0; i <= x; i++){
			cnt += d[i] * d[x-i];
		}
		cnt -= d[x/2];
		cout << cnt << endl;
	}
	
	return 0;
}