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 Kotlin (1.0.0) (judge verdict: Accepted)

import java.io.BufferedReader
import java.io.InputStream
import java.io.InputStreamReader
import java.util.StringTokenizer

fun main(args: Array<String>) {
    val sc = FastScanner(System.`in`)

    val s = sc.next()
    val t = sc.next()


    var best = ""
    for (i in 0..s.length - t.length) {
        if (test(i, s, t)) {
            val res = construct(i, s, t)
            if (best == "" || best > res) best = res
        }
    }
    println(if (best == "") "UNRESTORABLE" else best)

}

fun construct(i: Int, s: String, t: String): String {
    val sb = StringBuilder()
    for (j in 0 until i) {
        if (s[j] == '?') sb.append('a')
        else sb.append(s[j])
    }

    for (j in 0 until t.length) {
        sb.append(t[j])
    }
    for (j in i + t.length until s.length) {
        if (s[j] == '?') sb.append('a')
        else sb.append(s[j])
    }
    return sb.toString()
}

fun test(i: Int, s: String, t: String): Boolean {
    if (i + t.length > s.length) return false
    for (j in 0 until t.length) {
        if (s[i + j] != '?' && s[i + j] != t[j]) return false
    }
    return true
}


class FastScanner(s: InputStream) {
    private var st = StringTokenizer("")
    private val br = BufferedReader(InputStreamReader(s))

    fun next(): String {
        while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())

        return st.nextToken()
    }

    fun nextInt() = next().toInt()
    fun nextLong() = next().toLong()
    fun nextLine() = br.readLine()
    fun nextDouble() = next().toDouble()
    fun ready() = br.ready()
}