#define _USE_MATH_DEFINES

#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset
#include <cmath>		//sqrt, ceil. M_PI, pow, sin
#include <ios>			//fixed
#include <iomanip>		//setprecision
#include <sstream>		//stringstream
#include <numeric>		//gcd, assumlate
#include <random>		//randam_device
#include <limits>		//numeric_limits

using namespace std;
constexpr long long int D_MOD = 1000000007;


int main() {

    int H, W;
    cin >> H >> W;

    int N = H * W;
    vector<int> A(N);

    for (int i = 0; i < N; i++) {
        cin >> A.at(i);
    }

    sort(A.begin(), A.end());

    for (int i = 0; i < H; i++) {
        for (int j = 0; j < W; j++) {
            cout << A.at(i * W + j);
            if (j == W - 1) {
                cout << endl;
            }
            else {
                cout << " ";
            }
        }
    }

    return 0;

}