import std.algorithm, std.conv, std.range, std.stdio, std.string;

void main()
{
  auto s = readln.chomp.dup, ns = s.length;
  auto t = readln.chomp, nt = t.length;

 loop: foreach_reverse (i; 0..ns-nt+1) {
    foreach (j; 0..nt)
      if (s[i+j] != '?' && s[i+j] != t[j]) continue loop;

    s[i..i+nt][] = t[];
    writeln(s.replace("?", "a"));
    return;
  }
  writeln("UNRESTORABLE");
}
