Ane and Bo often play badminton and have built a digital
scoreboard.
In badminton, players take turns to score points. A player
wins a set by being first to reach at least $21$ points and having at least
$2$ points more than the
opponent, or by being first to reach $30$ points.
Input
The score is given in the form $a\mathtt-b$, with Ane’s
points $a$ and Bo’s
points $b$, separated
by -. Both $a$ and $b$ are integers between $0$ and $30$.
Output
If Ane has won the set, output “A”. If Bo has won the set,
output “B”. If the set is still
in progress, output “?”. If the
scoreboard is broken and the given score cannot occur,
output “!”.
| Sample Input 1 |
Sample Output 1 |
21-18
|
A
|
| Sample Input 2 |
Sample Output 2 |
23-25
|
B
|
| Sample Input 3 |
Sample Output 3 |
17-2
|
?
|
| Sample Input 4 |
Sample Output 4 |
22-16
|
!
|
| Sample Input 5 |
Sample Output 5 |
0-0
|
?
|
| Sample Input 6 |
Sample Output 6 |
30-30
|
!
|
