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'''
# Read input from stdin and provide input before running code

name = raw_input('What is your name?\n')
print 'Hi, %s.' % name
'''
from collections import OrderedDict
t = int(raw_input())

while t:
	t-=1
	n = int(raw_input())
	ni = OrderedDict([])
	for i in range(n):
		item = raw_input()
		ni[item] = True
		
	l = ni.keys()
	l.sort()
	for item in l:
		print item