import sys
import math

import random

C=set()


def dfs(id,s,cur):
	global K
	global prev
	global C
	if id==N:
		if cur!=prev:
			C.add(cur)
			if len(C)>2*K:
				C=list(C)
				C.sort()
				C.reverse()
				for c in C[:K]:
					print(c)
				sys.exit(0)
			
			prev = cur
		return
		
	for i in range(N):
		if i not in s:
			if i>0 and A[i]==A[i-1] and (i-1) not in s:
				continue
			s.add(i)
			dfs(id+1,s,cur+A[i])
			s.remove(i)

N,K=map(int,raw_input().strip().split(" "))
A=raw_input().strip().split(" ")
prev=""

for x in range(N):
	for i in range(N-1):
		if A[i]+A[i+1] < A[i+1]+A[i] or (A[i]+A[i+1] == A[i+1]+A[i] and A[i]<A[i+1]):
			A[i],A[i+1]=A[i+1],A[i]

dfs(0,set(),"")