import qualified Data.Text as T
import qualified Data.Text.IO as T
import qualified Data.Text.Read as T

main :: IO ()
main = do
  (n : _) <- map unsafeSignedDecimal . T.words <$> T.getLine :: IO [Int]
  s <- T.getLine :: IO T.Text
  T.putStrLn . T.map f $ s

f :: Int -> Char -> Char
f n = toEnum . (+ 65) . (`mod` 26) . (+ n) . subtract 65 . fromEnum

unsafeSignedDecimal :: T.Text -> Int
unsafeSignedDecimal s = case T.signed T.decimal s of
  Right (n, _) -> n
