Score : 400 points
Mr. Takahashi has a string s consisting of lowercase English letters. He repeats the following operation on s exactly K times.
z is a.For example, if you perform an operation for the second letter on aaz, aaz becomes abz.
If you then perform an operation for the third letter on abz, abz becomes aba.
Mr. Takahashi wants to have the lexicographically smallest string after performing exactly K operations on s. Find the such string.
The input is given from Standard Input in the following format:
s K
Print the lexicographically smallest string after performing exactly K operations on s.
xyz 4
aya
For example, you can perform the following operations: xyz, yyz, zyz, ayz, aya.
a 25
z
You have to perform exactly K operations.
codefestival 100
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