#include <bits/stdc++.h>

using namespace std;

int main() {
    int H, W;
    cin >> H, W;

    map<int, int> mp;
    for (int i = 0; i < H; ++i) {
        for (int j = 0; j < W; ++j) {
            int t;
            cin >> t;
            mp[t]++;
        }
    }

    int cur = 0;
    for (int i = 0; i < H; ++i) {
        for (int j = 0; j < W; ++j) {
            while (mp[cur] == 0) cur++;
            cout << cur << " ";
            mp[cur]--;
        }
        cout << endl;
    }
    return 0;
}