p02447 Sorting Pairs_5121
Write a program which print coordinates $(x_i, y_i)$ of given $n$ points on the plane by the following criteria.

1. first by $x$-coordinate
2. in case of a tie, by $y$-coordinate

Constraints

* $1 \leq n \leq 100,000$
* $-1,000,000,000 \leq x_i, y_i \leq 1,000,000,000$

Input

The input is given in the following format.


$n$
$x_0 \; y_0$
$x_1 \; y_1$
:
$x_{n-1} \; y_{n-1}$


In the first line, the number of points $n$ is given. In the following $n$ lines, coordinates of each point are given.

Output

Print coordinate of given points in order.

Example

Input

5
4 7
5 5
2 3
6 8
2 1


Output

2 1
2 3
4 7
5 5
6 8
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main()
{
    int n;
    cin >> n;
    vector<pair<int, int>> A;
    A.reserve(n); //要素数を予約
    for (int i = 0; i < n; i++)
    {
        int x, y;
        cin >> x >> y;
        A.push_back(make_pair(x, y));
    }
    sort(A.begin(), A.end());

    for (auto it = A.begin(); it != A.end(); it++)
    {
        // pair<int, int> P = *it;
        cout << it->first << ' ' << it->second << endl;
    }
}
