include<iostream>
using namespace std;
int main(){
    int t;
    cout<<"no. of cases:";
    cin>>t;
    while(t>0){
        int n;
        cout<<"size of array:";
        cin>>n;
        int arr[1000];
        for(int i=0;i<n;i++){
            cin>>arr[i];
        }
        int sum;
        cout<<"sum:";
        cin>>sum;
        int pair=0;
        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++){
                if(sum==arr[i]+arr[j]){
                pair++;
                }
            }
        }
        cout<<pair/2;

        t--;
    }
}