For Valentine's day, AQT wants to give a letter to his valentine. He currently has a string of lowercase letters and wants to give one to his valentine that isn't present in the string. Help him find one!
consists only of the letters
abcdefghijklmnopqrstuvwxyz (lowercase English alphabet).
The first line contains the string .
Output a letter that AQT does not have.
Note: If there are multiple letters that meet this criterion, output the one with lowest alphabetical order. See sample explanation for more details.
The letters AQT doesn't have are
bfghijklmnopqrstuvwxy. Out of all of them,
b is the one that comes first in the alphabet.