#include <iostream>
#include <stdio.h>
#include <string>
#include <vector>

using namespace std;

int main(){
    int teste;
    int n;
    float absci;
    float ordo;
    float centru_absci = 0;
    float centru_ordo = 0;
    vector<float> abscise;
    vector<float> ordonate;
    vector<int> contoare;
    vector<int> nr_n;
    int cont;
    vector<float> centrex;
    vector<float> centrey;
    cin >> teste;
    for(int i=0;i<teste;i++){
        cin >> n;
        nr_n.push_back(n);
        for(int j=0;j<n;j++){
            cin >> absci;
            cin >> ordo;
            abscise.push_back(absci);
            ordonate.push_back(ordo);
        }
        for(int a=0;a<n;a++){
            centru_absci += abscise[a];
            centru_ordo += ordonate[a];
        }
        centru_absci = centru_absci/n;
        centru_ordo = centru_ordo/n;
        centrex.push_back(centru_absci);
        centrey.push_back(centru_ordo);
        cont = 0;
        for(int c=0;c<n;c++){
            //cont = 0;
            for(int d=c+1;d<n;d++){
                if(abscise[c] = 2*centru_absci - abscise[d])
                    if(ordonate[c] = 2*centru_ordo - ordonate[d])
                        cont++;
            }
        }
        contoare.push_back(cont);
        centru_ordo = 0;
        centru_absci = 0;
        }
    }

    for(int i=0;i<teste;i++){
       cout<<"\n" <<centrex[i] <<" "<<centrey[i]<<"\n";
       /*
        if(contoare[i] == nr_n[i])
            printf("1 %.4f %.4f\n",centrex[i],centrey[i]);
        else
            printf("0\n");
            */
    }
    return 0;
}