import java.util.Arrays;
import java.util.Scanner;

public class HelloWorld {

	    public static void main(String[] args) throws Exception {

	    	Scanner sc = new Scanner(System.in);
	    	int number_rows = sc.nextInt();
	    	int number_columns = sc.nextInt();
	    	int[] data = new int[number_columns * number_rows];
	    	for (int i = 0; i < number_rows * number_columns; i ++) {
	    		data[i] = sc.nextInt();
	    	}

	    	Arrays.sort(data);

	    	for (int i = 0; i < number_rows; i++) {
	    		for (int j = 0; j < number_columns; j++) {
	    			System.out.print(data[i * number_columns + j]);
	    			if (j != number_columns - 1) {
	    				System.out.print(" ");
	    			}
	    		}
	    		System.out.println("");
	    	}

	    	}



}