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: Accepted)

main :: IO ()
main = do
  s' <- getLine
  t <- getLine
  putStrLn $ restore s' t

restore :: String -> String -> String
restore s' t =
  _restoreLoop (length s' - length t)
  where
    _restoreLoop :: Int -> String
    _restoreLoop start
      | start < 0 = "UNRESTORABLE"
      | otherwise = if isContained s' t start
                      then
                        let s'' = take start s' ++ t ++ drop (start + length t) s'
                        in map (replace 'a') s''
                      else
                        _restoreLoop (start - 1)

isContained :: String -> String -> Int -> Bool
isContained s' t start =
  all (\i -> t!!i == s'!!(start + i) || s'!!(start + i) == '?') [0..length t　- 1]

replace :: Char -> Char -> Char
replace c '?' = c
replace _ c0 = c0