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`.
from copy import deepcopy
s = list(input())
t = list(input())
lens = len(s)
lent = len(t)
ans = deepcopy(s)
for i in range(len(s)):
  if s[i] == "?":
    ans[i] = "a"
def match(moji):
  for i in range(lent):
    if moji[i] != t[i] and moji[i] != "?":
      return False
  return True
for i in range(lent, lens):
  ns = s[lens-i:lens-i+lent]
  if match(ns):
    ans[lens-i:lens-i+lent] = t
    print(ans)
    exit()
print("UNRESTORABLE")
from copy import deepcopy
s = list(input())
t = list(input())
lens = len(s)
lent = len(t)
ans = deepcopy(s)
for i in range(len(s)):
  if s[i] == "?":
    ans[i] = "a"
def match(moji):
  for i in range(lent):
    if moji[i] != t[i] and moji[i] != "?":
      return False
  return True
for i in range(lent, lens+1):
  ns = s[lens-i:lens-i+lent]
  if match(ns):
    ans[lens-i:lens-i+lent] = t
    print("".join(ans))
    exit()
print("UNRESTORABLE")