import Data.Char

main::IO()
main = do
  dat<-getLine
  cn<-getLine
  let n = read cn::Int
  putStr (solve n dat)
  putStr "\n"

solve :: Int -> String -> String
solve k [c]  = [num_to_char (mod ((char_to_num c)+k) 26)]
solve k ('a':cs)='a':(solve k cs)
solve k (c:cs) = let to_a = (26 - (char_to_num c)) in
                    if ((k >= to_a) && (to_a > 0)) then  'a':(solve (k - to_a) cs) else c:(solve k cs)


char_to_num::Char -> Int
char_to_num c = (ord c)-97

num_to_char::Int -> Char
num_to_char n = chr (n + 97)