cases_count = int(input())
for case_id in range(1, cases_count + 1):
mobile_count = int(input())
mobile_numbers = [input() for _ in range(mobile_count)]
jalil_number = input()
print(f"Case {case_id}:")
for current_number in mobile_numbers:
dif = 0
for i in range(len(current_number)):
if current_number[i] != jalil_number[i]:
dif += 1
if dif <= 1:
print(current_number)