package com.company;

import java.util.*;


public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int[] dimensions = getDimensions(scanner);
        int rows = dimensions[0];
        int cols = dimensions[1];
        int counter = 0;
        int[][] matrix = getMatrix(scanner, rows, cols);
        LinkedHashMap<Integer, ArrayList<Integer>> map = new LinkedHashMap<>();
        for (int r = 0; r < matrix.length; r++) {
            counter = r;
            for (int c = 0; c < matrix[0].length; c++) {
                if (c + r == counter) {
                    map.putIfAbsent(c + r, new ArrayList<>());
                    map.get(c + r).add(matrix[r][c]);
                }
                counter++;
            }
        }
        LinkedHashMap<Integer, ArrayList<Integer>> newMap = new LinkedHashMap<>(map.size());
        for (int i = 0; i < map.size(); i++) {
            newMap.putIfAbsent(i, map.get(map.size() - 1 - i));
        }
        for (ArrayList<Integer> value : newMap.values()) {
            Collections.sort(value);
            for (int j = 0; j <= value.size() - 1; j++) {
                System.out.print(value.get(j) + " ");
            }
            System.out.println();

        }
    }

    private static int[][] getMatrix(Scanner scanner, int rows, int cols) {
        int[][] matrix = new int[rows][cols];
        for (int r = 0; r < matrix.length; r++) {
            int[] arr = Arrays.stream(scanner.nextLine().split(" "))
                    .mapToInt(Integer::parseInt)
                    .toArray();
            matrix[r] = arr;
        }
        return matrix;
    }

    private static int[] getDimensions(Scanner scanner) {
        int[] dimensions = Arrays.stream(scanner.nextLine().split(" "))
                .mapToInt(Integer::parseInt)
                .toArray();
        return dimensions;
    }
}