Score : $300$ points
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:
Print the string $S$.
If such a string does not exist, print UNRESTORABLE.
?.Input is given from Standard Input in the following format:
$S$ $T'$
Print the string $S$.
If such a string does not exist, print UNRESTORABLE instead.
?tc???? coder
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.
??p??d?? abc
UNRESTORABLE
There is no string that satisfies Condition 1, so the string $S$ does not exist.