output_description: Print the string S.  
  If such a string does not exist, print `UNRESTORABLE` instead.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
      T'
attempt: import copy
  S_dash = input()
  T = input()
  
  len_S = len(S_dash)
  len_T = len(T)
  
  candidate0 = list(S_dash)
  
  
  ans = "z"*51
  
  if len_S >= len_T:
    for s in range(len_S):
      cha_S = S_dash[s]
      if cha_S != "?" and cha_S in list(T):
        for t in range(len_T):
          cha_T = T[t]
          if cha_S == cha_T:
            S_cut = S_dash[s-t:s-t+len_T]
            
            candidate1 = copy.deepcopy(candidate0)
            
            for x in range(len_T):
              if S_cut[x] == "?":
                candidate1[s-t+x] = T[x]
              elif  S_cut[x] != T[x]:
                break
            
            else:
              if candidate1[s-t:s-t+len_T].count("?") == 0:
                if ans > "".join(candidate1).replace('?', 'a'):
                  ans = "".join(candidate1).replace('?', 'a')
                  
  if ans = "z"*51:
    ans = "UNRESTORABLE"
  print(ans)
problem_description: 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`.
samples: [{"input": "?tc????\n    coder", "output": "atcoder\n    \n\nThere are 26 strings that satisfy Condition 1: `atcoder`, `btcoder`,\n`ctcoder`,..., `ztcoder`. Among them, the lexicographically smallest is\n`atcoder`, so we can say S = `atcoder`.\n\n* * *"}, {"input": "??p??d??\n    abc", "output": "UNRESTORABLE\n    \n\nThere is no string that satisfies Condition 1, so the string S does not exist."}]