Badminton is a widely played racket sport in Denmark. A
badminton match consists of sets; you play the best of three
sets. A player wins a set by being the first to reach at least
$21$ points and
having at least $2$ points more than the
opponent, or by being the first to reach $30$ points.
Ane and Bo have upgraded their fully automatic score
counter, so they can now record entire matches; they just need
to implement the logic for determining the winner of the
match.
Input
The input consists of a sequence of set scores separated by
spaces. Each set consists of $2$ point values separated by a
hyphen, -. Each point value is an
integer, at least $0$ and
at most $30$. The first
value is Ane’s points, the second is Bo’s.
Output
If Ane has won the match, write “A”. If Bo has won the match,
output “B”. If the match is
still ongoing, write “?”. If the
score counter is broken and the given score cannot occur in a
correctly played and recorded badminton match,
write “!”.
| Sample Input 1 |
Sample Output 1 |
21-0 21-0
|
A
|
| Sample Input 2 |
Sample Output 2 |
21-0 19-21 29-30
|
B
|
| Sample Input 3 |
Sample Output 3 |
0-0
|
?
|
| Sample Input 4 |
Sample Output 4 |
21-18 1-5
|
?
|
| Sample Input 5 |
Sample Output 5 |
21-18 0-0
|
?
|
| Sample Input 6 |
Sample Output 6 |
21-18 21-0 21-0 0-0
|
!
|
| Sample Input 7 |
Sample Output 7 |
0-0 0-0
|
!
|
