while(num--){
        int n;
        cin >> n;

        set < pair<int, int> > S;
        set < pair<int, int> >::iterator it;
        set < pair<int, int> >::iterator it2;

        vector <int> x;
        vector <int> y;

        int a, b;
        for(int i=0; i<n; i++){
            scanf("%d%d", &a, &b);
            x.push_back(a);
            y.push_back(b);
            S.insert(make_pair(a, b));
        }

        int temp_x;
        int temp_y;
        int MAX = 0;

        for(int i=0; i<n; i++){
            for(int j=i+1; j<n; j++){
                temp_x = x[j] - x[i];
                temp_y = y[j] - y[i];

                it = S.find(make_pair(x[j]-temp_y, y[j] + temp_x));
                it2 = S.find(make_pair(x[j]-temp_y -temp_x, y[j] + temp_x -temp_y));
                //it = S.find(make_pair(3, 10));
                if(it != S.end() && it2 != S.end()){
                    MAX = max(MAX, (int)pow((double)(temp_x), 2) + (int)pow((double)(temp_y), 2));
                    continue;
                }

                it = S.find(make_pair(x[j]+temp_y, y[j] -temp_x));
                it2 = S.find(make_pair(x[j]+temp_y-temp_x, y[j]-temp_x-temp_y));
                if(it != S.end() && it2 != S.end())
                    MAX = max(MAX, (int)pow((double)(temp_x), 2) + (int)pow((double)(temp_y), 2));

            }
        }

        cout << MAX << endl;
    }