#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++)
#define ALL(x) (x).begin(), (x).end()

const double PI = acos(-1);

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int h, w;
  cin >> h >> w;

  vector<int> v;
  REP (i, h) REP (j, w) {
    int tmp;
    cin >> tmp;
    v.push_back(tmp);
  }

  sort(v.begin(), v.end());
  REP (i, h) {
    REP (j, w)
      cout << v[i*w+j] << " ";
    cout << endl;
  }
  
  
  
  return 0;
}