import Control.Monad

suc :: Char -> [Char]
suc 'Z' = "AA"
suc c = [succ c]

suc' :: [Char] -> [Char]
suc' [] = "A"
suc' s
    | length c == 2 = (suc' $ init s) ++ [last c]
    | otherwise = init s ++ c
    where
        c = suc $ last s

solve :: Integer -> String -> String
solve 0 s = s
solve n s = solve (pred n) (suc' s)

main = do
    n <- readLn
    putStrLn $ solve n "A"