Coordinate.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.StringTokenizer;

class Coodinate {

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        int N = Integer.parseInt(br.readLine());

        int[][] arr = new int[N][2];
        StringTokenizer st;

        for (int i = 0; i < N; i++) {
            st = new StringTokenizer(br.readLine());
            for (int j = 0; j < 2; j++) {
                arr[i][j] = Integer.parseInt(st.nextToken());
            }
        }

        Arrays.sort(arr, new Comparator<int[]>() {
            @Override
            public int compare(int[] num1, int[] num2) {
                if(num1[0] == num2[0]) {
                    return num1[1] - num2[1];
                }
                else {
                    return num1[0] - num2[0];
                }
            }
        });

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < arr.length; i++) {
            sb.append(arr[i][0] + " " + arr[i][1]).append("\n");
        }

        bw.write(sb.toString());
        bw.flush();
        bw.close();
        br.close();
    }
}