#include <iostream>


using namespace std;


struct treap {
    struct node {
        node* left;
        node* right;
        int x;
        int y;

        node(int _x, int _y) {
            left = nullptr;
            right = nullptr;
            x = _x;
            y = _y;
        }

    };

    using node_ptr = node*;

    node_ptr root;

    treap() {
        root = nullptr;
    }

    node_ptr merge(node_ptr t1, node_ptr t2) {
        if(t1 == nullptr) return t2;
        if(t2 == nullptr) return t1;

        if(t1->y < t2->y) {
            t1->right = merge(t1->right, t2);
            return t1;
        } else {
            t2->left = merge(t1, t2->left);
            return t2;
        }
    }

    void split(node_ptr t, int x0, node_ptr & t1, node_ptr & t2) {
        if(t == nullptr) {
            t1 = nullptr;
            t2 = nullptr;
            return;
        }

        if(x0 > t->x) {
            split(t->right, x0, t->right, t2);
            t1 = t;
        } else {
            split(t->left, x0, t1, t->left);
            t2 = t;
        }
    }

    void insert(int _x, int _y) {
        node_ptr l = nullptr;
        node_ptr r = nullptr;
        node_ptr m = new node(_x, _y);

        split(root, _x, l, r);
        root = merge(merge(l, m), r);
    }

    void print() {
        print(root, 0);
    }

    void print(node_ptr t, int h) {
        if(t == nullptr) return;

        print(t->left, h + 1);

        for(int i = 0; i < h; i++) cout << "\t\t";
        cout << "(" << t->x << ", " << t->y << ")" << endl;

        print(t->right, h + 1);
    }
};


int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    treap t;
    int q;

    cin >> q;

    while(q--) {
        int x, y;
        cin >> x >> y;

        t.insert(x, y);
    }

    t.print();
    cout << "End of program..." << endl;

    return 0;
}