#include <bits/stdc++.h>
using namespace std;
 
int main()
{
	int H, W;
	cin >> H >> W;
	vector<vector<int>> A( H, vector<int>( W ) );
	for( int i = 0; i < H; i++ ) {
		for( int j = 0; j < W; j++ ) {
			cin >> A[i][j];
		}
	}

	vector<int> a;
	for( int j = 0; j < W; j++ ) {
		for( int i = 0; i < H; i++ ) {
			a.push_back( A[i][j] );
		}
	}
	sort( a.begin(), a.end() );
	for( int i = 0; i < H; i++ ) {
		for( int j = 0; j < W; j++ ) {
			A[i][j] = a[i * W + j];
		}
	}

	for( int i = 0; i < H; i++ ) {
		for( int j = 0; j < W; j++ ) {
			if( j ) cout << " ";
			cout << A[i][j];
		}
		cout << endl;
	}
}