/* -*- coding: utf-8 -*-
 *
 * 1130.cc:  No.1130 Grid Numbers - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_H = 100;
const int MAX_W = 100;
const int MAX_N = MAX_H * MAX_W;

/* typedef */

/* global variables */

int as[MAX_N];

/* subroutines */

/* main */

int main() {
  int h, w;
  scanf("%d%d", &h, &w);
  int n = h * w;

  for (int i = 0; i < n; i++) scanf("%d", as + i);
  sort(as, as + n);

  for (int i = 0, p = 0; i < h; i++)
    for (int j = 0; j < w; j++, p++) {
      printf("%d", as[p]);
      putchar(j + 1 < w ? ' ' : '\n');
    }
  return 0;
}