#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int h, w;
  cin >> h >> w;
  vector<int> a(h * w);
  rep(i, h * w) cin >> a[i];
  sort(a.begin(), a.end());
  rep(i, h) {
    rep(j, w) cout << a[i * w + j] << " ";
    cout << endl;
  }
  return 0;
}