Problem:
Score : 300 points

Problem Statement

E869120 found a chest which is likely to contain treasure.

However, the chest is locked. In order to open it, he needs to enter a string S consisting of lowercase English letters.

He also found a string S', which turns out to be the string S with some of its letters (possibly all or none) replaced with ?.

One more thing he found is a sheet of paper with the following facts written on it:

Condition 1: The string S contains a string T as a contiguous substring.

Condition 2: S is the lexicographically smallest string among the ones that satisfy Condition 1.

Print the string S.

If such a string does not exist, print UNRESTORABLE.

Constraints

1 \leq |S'|, |T| \leq 50

S' consists of lowercase English letters and ?.

T consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S
T'

Output

Print the string S.

If such a string does not exist, print UNRESTORABLE instead.

Sample Input 1

?tc????
coder

Sample Output 1

atcoder

There are 26 strings that satisfy Condition 1: atcoder, btcoder, ctcoder,..., ztcoder.
Among them, the lexicographically smallest is atcoder, so we can say S = atcoder.

Sample Input 2

??p??d??
abc

Sample Output 2

UNRESTORABLE

There is no string that satisfies Condition 1, so the string S does not exist.

Solution in Haskell (GHC 7.10.3) (judge verdict: Wrong Answer)

newtype FazzyChar   = FazzyChar {getFazzyChar :: Char}
type FazzyString = [FazzyChar]

instance Eq FazzyChar where
    FazzyChar '?' == FazzyChar _   = True
    FazzyChar _   == FazzyChar '?' = True
    FazzyChar c   == FazzyChar c'  = c == c'

main :: IO ()
main = do
    s <- getLine :: IO String
    t <- fromString <$> getLine :: IO FazzyString
    let str = map getFazzyChar $ restore (fromString s) t
    putStrLn $ if s == str then "UNRESTORABLE" else minString str

fromString :: String -> FazzyString
fromString = map FazzyChar

minString :: String -> String
minString = map (\c -> if c == '?' then 'a' else c)

restore s k = let
    ans = restore' s k
    in if ans == s then ans else restore ans k

restore' :: FazzyString -> FazzyString -> FazzyString
restore' [] _ = []
restore' fs key = if canConcertaion fs key
    then key ++ drop (length key) fs
    else head fs : restore' (tail fs) key
    where 
    canConcertaion _ [] = True
    canConcertaion [] _ = False
    canConcertaion (f:fs) (k:key) = (f == k) && canConcertaion fs key