15664.java

import java.util.*;

public class Main {
 
 public static void main(String[] args) {

 Scanner sc = new Scanner(System.in);

 int n = sc.nextInt();
 int m = sc.nextInt();

 arr = new int[n];
 check = new boolean[n];
 set = new HashSet<>();

 for(int i=0; i<n; i++) {
 arr[i] = sc.nextInt();
 }

 Arrays.sort(arr);
 go(new int[m], 0, 0);

 }

 static int[] arr;
 static boolean[] check;
 static HashSet<String> set;

 static String convert(int[] sel) {
 StringBuilder sb = new StringBuilder();
 
 for(int i=0; i<sel.length; i++) {
 sb.append(sel[i]);
 sb.append(" ");
 }
 
 return sb.toString(); 
 }
 
 static void go(int[] sel, int sel_idx, int arr_idx) {
 
 if(sel_idx == sel.length) {
 String str = convert(sel);
 
 if(!set.contains(str)) {
 set.add(str);
 System.out.println(str);
 }
 
 return;
 }

 if(arr_idx == arr.length)
 return;
 
 sel[sel_idx] = arr[arr_idx];
 go(sel, sel_idx+1, arr_idx+1);
 go(sel, sel_idx, arr_idx+1);
 }
 
}