#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    int h, w;
    cin >> h >> w;
    vector<int> x(h*w);
    for (int i = 0; i < h*w; i++) cin >> x[i];
    sort(x.begin(), x.end());
    string delim = "";
    int cnt = 0;
    for (auto y : x){
        cout << delim << y;
        cnt++;
        delim = " ";
        if (!(cnt%w)){
            cout << endl;
            cnt = 0;
            delim = "";
        }
        
    }
}