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)

import Control.Applicative
import Control.Monad
import Data.List
import Data.Char
strToInt s = (read :: String -> Int) s

main :: IO ()
main = do
    -- 文字列の入力
    ss <- getLine
    ts <- getLine
    -- 出力
    putStrLn $ solve ss ts

isPre :: String -> String -> Bool
isPre [] _ = False
isPre _ [] = True
isPre (s:ss) (t:ts) = if s == '?' || s == t then isPre ss ts else False

replace :: String -> Int -> String -> String
replace ss k ts = map (\c -> if c == '?' then 'a' else c) (present ++ ts ++ latter)
    where
        present = take (length ss - k) ss
        latter  = drop (length present + length ts) ss

solve :: String -> String -> String
solve ss ts = if null cands then "UNRESTORABLE" else replace ss (length $ head cands) ts
    where
        cands = dropWhile (not . flip isPre ts) (tails ss)