import static java.lang.System.out;
import java.lang.Math;
import java.io.InputStream;
import java.io.IOException;
import java.util.NoSuchElementException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.Collections;

public class Main {
    public static void main(String args[]) {
        new Main().run();
    }

    MyInput in = new MyInput();
    public void run() {
        String Sd = in.next();
        String T = in.next();
        int count = 0;
        char c;
        boolean ok = false;
        int first = -1;
        int end = -1;
        for(int j = 0; j < Sd.length(); j++) {
            count = 0;
            for(int i = 0; i+j < Sd.length(); i++) {
                c = Sd.charAt(i+j);
                if(c == '?' || c == T.charAt(count)) {
                    count++;
                    if(count == T.length()) {
                        first = i+j - T.length() + 1;
                        end = i+j;
                        ok = true;
                        break;
                    }
                }else count = 0;

            }
        }
        if(ok) {
            for(int i = 0; i < Sd.length(); i++) {
                if(first <= i && i <= end) {
                    out.print(T.charAt(i - first));
                }else {
                    if(Sd.charAt(i) == '?') out.print("a");
                    else out.print(Sd.charAt(i));
                }
            }
            out.println();
        }else {
            out.println("UNRESTORABLE");
        }
    }
}

class MyInput {
    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;
    }

    public int readByte() {
        if (hasNextByte()) return buffer[ptr++];
        else return -1;
    }

    private static boolean isPrintableChar(int c) {
        return 33 <= c && c <=126;
    }

    private void skipUnprintable() {
        while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
    }

    public boolean hasNext() {
        skipUnprintable();
        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: 23380