5
10
bb
bb
ab
aa
bb
bb
ba
aa
bb
ab
10
bb
ab
ba
ab
ba
ba
ab
ba
ba
ba
10
aa
ba
ba
ba
bb
ab
ab
aa
bb
bb
10
ab
ab
bb
bb
ab
ba
aa
ba
ab
aa
10
ba
bb
bb
bb
aa
ba
ba
ba
bb
bb
aa
ab
ba
bb
ab
ba
bb
aa
ab
ba
bb
aa
ab
ba
bb
aa
ba
bb

def acc():
	n = int(input())
	if 1<=n<=10**5:
		l = []
		for i in range(0, n):
			r = raw_input()
			if 1<=len(r)<=10**5 and (r not in l):
				l.append(r)
			
		for j in sorted(l):
			print j
t = int(input())
if 1<=t<=10:
	
	for i in range(0, t):
		acc()