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`.
s1 = input()
t = input()
n = len(s1)
m = len(t)

def check(i):
    for j in range(m):
        if not (s1[i+j] == t[j] or s1[i+j] == "?"):
            return False
    return True
            
def run():
    i = 0
    for s in range(n-m):
        if s1[s] == t[0] or s1[s] == '?':
            if check(i):
                return i
        i += 1
    return -1
i = run()
if i == -1:
    print("UNRESTORABLE");exit()
li = []
for j in range(n):
    if i==j:
        li += t
    elif i<=j<(i+m):
        continue
    elif s1[j] == "?":
        li.append("a")
    else:
        li.append(s1[j])

print("".join(li))

S = input()[::-1]
T = input()[::-1]
n = len(S);m = len(T)
a = []
for i in range(0, n - m + 1):
    f = 1
    s = S[i:i+m]
    for j in range(m):
        if s[j] not in ["?",T[j]]:
            f = 0
            break
    if f:
        a = S[:i] + T + S[i+m:]
        break

if a:
    print(a.replace('?','a')[::-1])
else:
    print('UNRESTORABLE')
