class Solution {

public:

    int numberOfPairs(vector<vector<int>>& points) {

        int count = 0;

        for (int i = 0; i < points.size(); ++i) {

            for (int j = 0; j < points.size(); ++j) {

                if (i != j) {

                    int upperLeftX = min(points[i][0], points[j][0]);

                    int upperLeftY = max(points[i][1], points[j][1]);

                    int lowerRightX = max(points[i][0], points[j][0]);

                    int lowerRightY = min(points[i][1], points[j][1]);

                    bool noOneInside = true;

                    for (const auto& point : points) {

                        if (point != points[i] && point != points[j]) {

                            if (point[0] >= upperLeftX && point[0] <= lowerRightX &&

                                point[1] <= upperLeftY && point[1] >= lowerRightY) {

                                noOneInside = false;

                                break;

                            }

                        }

                    }

                    if (noOneInside) {

                        ++count;

                    }

                }

            }

        }

        return count;

    }

};