#include <bits/stdc++.h>

using namespace std;

int main()
{
    int h,w;
    scanf("%d%d", &h, &w);

    int elems{ h * w };
    vector<int> v(elems);
    for (int i = 0; i < elems; ++i)
        scanf("%d", &v[i]);

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

    stringstream ss;
    for (int i = 0; i < h; ++i)
    {
        for (int j = 0; j < w - 1; ++j)
            ss << v[i * w + j] << " ";

        ss << v[(i + 1) * w- 1] << "\n";
    }

    printf("%s", ss.str().c_str());

    return 0;
}