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

signed main(){
    ios::sync_with_stdio(false);
	cin.tie(0);
 
    ll n,x;
    cin>>n>>x;
    ll a[111111]={};
    for(int i=0;i<n;i++){
        int b;
        cin>>b;
        a[b]++;
    }
    ll ans=0;
    for(int i=0;i<=x/2;i++){
        if(x-i>101010) continue;
        if(i==x/2 && i*2==x){
            ans+= a[i]*a[i];
        }
        else ans += 2*a[i]*a[x-i];
    }
    cout<<ans<<endl;

}