Bear and String Distance
Description
Limak is a little polar bear. He likes nice strings — strings of length n, consisting of lowercase English letters only.
The distance between two letters is defined as the difference between their positions in the alphabet. For example, 
, and 
.
Also, the distance between two nice strings is defined as the sum of distances of corresponding letters. For example, 
, and 
.
Limak gives you a nice string s and an integer k. He challenges you to find any nice string s' that 
. Find any s' satisfying the given conditions, or print "-1" if it's impossible to do so.
As input/output can reach huge size it is recommended to use fast input/output methods: for example, prefer to use gets/scanf/printf instead of getline/cin/cout in C++, prefer to use BufferedReader/PrintWriter instead of Scanner/System.out in Java.
The first line contains two integers n and k (1 ≤ n ≤ 105, 0 ≤ k ≤ 106).
The second line contains a string s of length n, consisting of lowercase English letters.
If there is no string satisfying the given conditions then print "-1" (without the quotes).
Otherwise, print any nice string s' that 
.
Input
The first line contains two integers n and k (1 ≤ n ≤ 105, 0 ≤ k ≤ 106).
The second line contains a string s of length n, consisting of lowercase English letters.
Output
If there is no string satisfying the given conditions then print "-1" (without the quotes).
Otherwise, print any nice string s' that .
Samples
4 26
bear
roar
2 7
af
db
3 1000
hey
-1