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

for i in range(int(raw_input())):
	lis = []
	for i in range(int(raw_input())):
		lis.append(raw_input())
	lis = sorted(list(set(lis)))
	for li in lis:
		print li