import sys
import math

import random
 
def is_Prime(n):
    """
    Miller-Rabin primality test.
 
    A return value of False means n is certainly not prime. A return value of
    True means n is very likely a prime.
    """
    if n!=int(n):
        return False
    n=int(n)
    #Miller-Rabin test for prime
    if n==0 or n==1 or n==4 or n==6 or n==8 or n==9:
        return False
 
    if n==2 or n==3 or n==5 or n==7:
        return True
    s = 0
    d = n-1
    while d%2==0:
        d>>=1
        s+=1
    assert(2**s * d == n-1)
 
    def trial_composite(a):
        if pow(a, d, n) == 1:
            return False
        for i in range(s):
            if pow(a, 2**i * d, n) == n-1:
                return False
        return True  
 
    for i in range(12):#number of trials 
        a = random.randrange(2, n)
        if trial_composite(a):
            return False
 
    return True

def dfs(id,s,cur):
	global K
	global prev
	if id==N:
		if cur!=prev:
			print(cur)
			K -= 1
			if K==0:
				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(),"")