import Data.List

main :: IO ()
main = do
  n <- readLn
  s <- getLine
  putStrLn $ ans n s

ans :: Int -> String -> String
ans n = map shiftS where
  alf = ['A'..'Z']
  shiftS c = alf !! ((`mod` 26) . (+n) . (\(Just a) -> a) $ elemIndex c alf)