#include <bits/stdc++.h>
#define rep(i,n) for(int i=(0);i<(n);i++)

using namespace std;

typedef long long ll;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	ll x;
	cin >> n >> x;

	vector<ll> a(n);
	rep(i, n) cin >> a[i];

	map<ll, int> mp;
	rep(i, n){
		if(mp.count(a[i]) == 0) mp[a[i]] = 0;
		mp[a[i]]++;
	}

	ll ans = 0;
	rep(i, n){
		if(mp.count(x - a[i]) > 0){
			ans += mp[x - a[i]];
		}
	}

	cout << ans << endl;	
}