#include <bits/stdc++.h>
using namespace std;

int main() {
    
    int n;int tg;
    cin>>n;cin>>tg; 
    vector <int> ar;
    for(int i=0;i<=n-1;i++){
    	int y;cin>>y; 
    	ar.push_back(y); 
    }
    

    int ct = 0;
    unordered_map<int, int> mp;

    for (int j = 0; j < n; j++) {
        int df = tg - ar[j];

        if (mp.count(df)) {
            ct += mp[df];
        }

        mp[ar[j]]++;
    }

    cout << ct << endl;

    return 0;
}