import java.util.*;


public class Mymerge {
    public static void main(String[] args) {
        Random rand = new Random();
        int n = rand.nextInt(10);
        System.out.println("n=" + n);
        int[][] a = new int[n][2];

        for (int i = 0; i < n; i++) {
            a[i][0] = rand.nextInt(10);
            a[i][1] = rand.nextInt(10);
        }

        Sliyaniye(a, 0, a.length - 1);
        out(a);
    }

    public static void Sliyaniye(int[][] a, int start, int end) {
        if (start < end) {

            Sliyaniye(a, start, (start + end) / 2);
            Sliyaniye(a, (start + end) / 2 + 1, end);

            Merge(a, start, end);
        }
    }

    public static void Merge(int[][] a, int start, int end) {
        int l, r, m;
        int[][] temp = new int[end-start+1][2];
        m = (start + end) / 2;
        l = start;
        r = m + 1;
        for (int j = start; j <= end; j++) {
            if ((l <= m) && ((r > end) || (a[l][0] < a[r][0]) || (a[l][0] == a[r][0] && a[l][1] < a[r][1]))) {
                temp[j - start][0] = a[l][0];
                temp[j - start][1] = a[l][1];
                l++;
            } else {
                temp[j - start][0] = a[r][0];
                temp[j - start][1] = a[r][1];
                r++;
            }
        }
        out(temp);

        for (int j = start; j <= end; j++) {
            a[j] = temp[j - start];
        }
    }

    public static void out(int[][] a) {
        System.out.println();
        for (int r[] : a) {
            System.out.println(r[0] + " " + r[1]);
        }
    }
}