tmp = input()
chars = set(tmp)
dic = {char: tmp.count(char) for char in chars}
minval = min(dic.values())
for char in dic:
if dic[char] == minval:
tmp = tmp.replace(char, '')
print(tmp)
tmp = input()
chars = set(tmp)
dic = {char: tmp.count(char) for char in chars}
minval = min(dic.values())
for char in dic:
if dic[char] == minval:
tmp = tmp.replace(char, '')
print(tmp)