#include<iostream>
#include<algorithm>

using namespace std;
#define int long long
#define repeat(i,n) for(int i=0;i<(n);i++)

signed main(){

   int N, X;
   cin>> N>> X;
   int a[N];
   repeat(i, N) cin>> a[i];

   sort(a, a+N);
   int ans=0;
   for(int e: a){
      ans+=distance(lower_bound(a, a+N, X-e),
                    upper_bound(a, a+N, X-e));
   }

   cout<< ans<< endl;

   return 0;
}