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)

my_equal::Char->Char->Bool
my_equal c d = case (c,d) of
              ('?',_) -> True
              (_,'?') -> True
              (a,b)   -> a==b

try_gen::String->String->Maybe String
try_gen rest   []      = Just rest
try_gen []     (y:rest)  = Nothing
try_gen (x:xs) (y:ys)  = if my_equal x y then case try_gen xs ys of
                                                Nothing   -> Nothing
                                                Just rest -> Just (y:rest)
                                         else Nothing

total_case::String->String->[Maybe String]
total_case [] t = []
total_case (s:ss) t = (try_gen (s:ss) t):(map (\x -> case x of
                                                      Nothing -> Nothing
                                                      Just st -> Just (s:st)) (total_case ss t))

solver::String->String->String
solver s t = let ls =  filter (Nothing/=) (total_case s t) in
             case ls of
                []        -> "UNRESTORABLE"
                otherwise -> let Just str = last ls in map (\c-> if c =='?' then 'a' else c) str

main::IO()
main=do
  s<-getLine
  t<-getLine
  putStr (solver s t)
  putStr "\n"