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`.
import sys, os

f = lambda:list(map(int,input().split()))
if 'local' in os.environ :
    sys.stdin = open('./input.txt', 'r')

def solve():
    s = input()
    t = input()

    sl = len(s)
    tl = len(t)

    if t in s:
        for i in range(sl):
            if s[i]=='?':
                print('a', end='')
            else:
                print(s[i], end='')
        print()
        return

    contain = 0
    for i in range(sl-1, 0, -1):
        if i+tl-1>=sl:
            continue
        ok = 1
        for j in range(tl):
            if s[i+j] not in ['?', t[j]]:
                ok = 0
                break
        if ok:
            s = s[:i] + t + s[i+tl:]
            for i in range(sl):
                if s[i]=='?':
                    print('a', end='')
                else:
                    print(s[i], end='')
            return

    print('UNRESTORABLE')
            

solve()

import sys, os

f = lambda:list(map(int,input().split()))
if 'local' in os.environ :
    sys.stdin = open('./input.txt', 'r')

def solve():
    s = input()
    t = input()

    sl = len(s)
    tl = len(t)

    if t in s:
        for i in range(sl):
            if s[i]=='?':
                print('a', end='')
            else:
                print(s[i], end='')
        print()
        return

    for i in range(sl-1, -1, -1):
        if i+tl-1>=sl:
            continue
        ok = 1
        for j in range(tl):
            if s[i+j] not in ['?', t[j]]:
                ok = 0
                break
        if ok:
            s = s[:i] + t + s[i+tl:]
            for i in range(sl):
                if s[i]=='?':
                    print('a', end='')
                else:
                    print(s[i], end='')
            
            print()
            return

    print('UNRESTORABLE')
            

solve()
