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 Rust (1.15.1) (judge verdict: Accepted)

use std::io::*;

fn main() {
    let stdin = stdin();

    let mut buf = String::new();
    stdin.read_line(&mut buf).ok();
    let mut s: Vec<u8> = buf.trim().bytes().collect();

    let mut buf = String::new();
    stdin.read_line(&mut buf).ok();
    let t: Vec<u8> = buf.trim().bytes().collect();

    let mut replaced = false;
    for i in (0..s.len()+1-t.len()).rev() {
        if matches(&t, &s[i..i+t.len()]) {
            for j in 0..t.len() {
                s[i+j] = t[j];
            }
            replaced = true;
            break;
        }
    }
    if replaced {
        let s_str: String = s.iter().map(|&s| s as char).collect();
        println!("{}", s_str.replace("?", "a"));
    } else {
        println!("UNRESTORABLE")
    }
}

fn matches(s: &[u8], p: &[u8]) -> bool {
    for i in 0..s.len() {
        if p[i] != b'?' && s[i] != p[i] {
            return false;
        }
    }
    true
}