#include<iostream>
#include<string>

using namespace std;

int main(){
    int N,sum;
    int result = 0;

    cin >> N;
    cin >> sum;

    int* elem = new int[N];

    for(int i=0;i<N;i++){
        cin >> elem[i];
    }

    for(int i=0;i<N;i++){
        for(int j=i;j<N;j++){
            if((elem[i] + elem[j]) == sum){
                if(i != j){
                    result += 2;
                }else{
                    result += 1;
                }
            }
        }
    }

    cout << result <<endl;

    return 0;
}