import std.stdio, std.string, std.conv, std.algorithm;
import std.range, std.array, std.math, std.typecons, std.container, core.bitop;

immutable inf = 1<<30;
string ng = "UNRESTORABLE";

void main() {
    string s, t;
    scan(s);
    scan(t);

    int n = s.length.to!int, k = t.length.to!int;

    foreach_reverse (i ; 0 .. n - k + 1) {
        bool match = true;

        foreach (j ; i .. i + k) {
            if (s[j] == '?') continue;
            if (s[j] != t[j - i]) {
                match = false;
                break;
            }
        }

        if (match) {
            foreach (j ; 0 .. n) {
                if (i <= j && j < i + k) {
                    write(t[j - i]);
                }
                else {
                    write(s[j] == '?' ? 'a' : s[j]);
                }

                if (j == n - 1) {
                    writeln();
                }
            }

            return;
        }
    }

    writeln(ng);
}


void scan(T...)(ref T args) {
    string[] line = readln.split;
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}



void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}