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 $ solve s' t

solve :: String -> String -> String
solve s' t = let ans = filter (isConvertible s') $ candidates s' t
             in if null ans
                then "UNRESTORABLE"
                else toAns . last $ ans


toAns [] = []
toAns (s:ss)
  | s == '?' = 'a':toAns ss
  | otherwise = s:toAns ss

isConvertible :: String -> String -> Bool
isConvertible s candidate = all (\(x,y) -> x == y || x == '?') $ zip s candidate

candidates :: String -> String -> [String]
candidates s' t = encode s' t 0
encode :: String -> String -> Int -> [String]
encode s' t i
  | slength < tlength + i = []
  | otherwise = (top ++ t ++ bottom):encode s' t (i+1)
  where
    slength = length s'
    tlength = length t
    (top, middle) = splitAt i s'
    (_, bottom) = splitAt tlength middle