#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include<iostream>
#include<map>
#include<vector>

using namespace std;
using i32 = int_fast32_t;
using i64 = int_fast64_t;
#define rep(i, n) for (i32 i = 0; i < (i32)(n); i++)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
using P = pair<i64, i64>;

int main() {
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    i32 n, x;
    cin >> n >> x;
    vector<i32> a(n);
    map<i32, i32> mp;
    rep(i, n) {
        cin >> a[i];
        mp[a[i]]++;
    }
    i32 ans = 0;
    rep(i, n) {
        ans += mp[x - a[i]];
    }
    cout << ans << endl;
}