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)

import Control.Monad
import Data.Monoid
import Data.List
 
getInt = read <$> getLine :: IO Int
getInts = map read . words <$> getLine :: IO [Int]
 
f s t 0 
    | slen < tlen = Nothing
    | any (\(x, y) -> x/='?' && x/=y) pairs = Nothing
    | otherwise = Just (t ++ (map g $ drop tlen s))
    where
        slen = length s
        tlen = length t
        pairs = zip s t
        g c = if c=='?' then 'a' else c
f [] t n = Nothing
f (c:s) t n = (c':) <$> f s t (n-1)
    where c' = if c=='?' then 'a' else c
    
    
main = do
    s' <- getLine
    t <- getLine
    putStrLn $ maybe "UNRESTORABLE" id $ getLast $ foldMap Last $ map (\n -> f s' t n) [0..(length s')]