import java.util.*;
import java.io.*;

public class Main {

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);
		String S_ = sc.next();
		String T = sc.next();
		char[] t = T.toCharArray();
		List<String> list = new ArrayList<>();
		String ans = "UNRESTORABLE";
		
		int num = S_.length() - T.length() + 1;
		
		for(int i = 0; i < num; i++) {
			char[] s_ = S_.toCharArray();
			boolean flag = true;
			int cnt = 0;
			for(int j = i; j < i + t.length; j++) {
				if (s_[j] == '?') {
					s_[j] = t[cnt];
				} else if (s_[j] != t[cnt]) {
					//out.println("false");
					flag = false;
					break;
				} 
				cnt++;
			}
			if (flag) {
				for(int j = 0; j < s_.length; j++) {
					if (s_[j] == '?')
						s_[j] = 'a';
				}
			list.add(String.valueOf(s_));
			}
		}
		
		if (list.size() > 0) {
			ans = list.get(0);
		} 
		for(int i = 1; i < list.size(); i++) {
			String str = list.get(i);
			int com = str.compareTo(ans);
			if(com < 0)
				ans = str;
		}
		out.println(ans);

		out.close();
	}
	

static class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}
}



Measured memory_bytes: 22612