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 Go (1.6) (judge verdict: Wrong Answer)

package main

import "fmt"

func main() {
	var s, t string
	fmt.Scan(&s, &t)

	s, t = reverse(s), reverse(t)

	ti := 0
	ng := true
	for i := 0; i < len(s); i++ {
		if s[i] == '?' || (i < len(t)-1 && s[i] == t[i]) {
			ok := true
			for j := 0; j < len(t); j++ {
				if len(s)-1 <= i+j {
					ok = false
					break
				}
				if s[i+j] == '?' {
					continue
				}

				if s[i+j] != t[j] {
					ok = false
				}
			}
			if ok {
				ti = i
				ng = false
				break
			}
		}
	}

	if ng {
		fmt.Println("UNRESTORABLE")
		return
	}

	ans := ""
	for i := 0; i < len(s); i++ {
		if i == ti {
			for j := 0; j < len(t); j++ {
				ans += string(t[j])
			}
			i += len(t) - 1
		} else {
			if s[i] == '?' {
				ans += "a"
			} else {
				ans += string(s[i])
			}
		}
	}

	fmt.Println(reverse(ans))
}

func reverse(s string) string {
	t := ""
	for _, c := range s {
		t = string(c) + t
	}
	return t
}