#arc087c. [arc087_c]Prefix-free Game
[arc087_c]Prefix-free Game
Problem Statement
For strings and , we will say that and are prefix-free when neither is a prefix of the other.
Let be a positive integer. A set of strings is a good string set when the following conditions hold true:
- Each string in has a length between and (inclusive) and consists of the characters
0
and1
. - Any two distinct strings in are prefix-free.
We have a good string set . Alice and Bob will play a game against each other. They will alternately perform the following operation, starting from Alice:
- Add a new string to . After addition, must still be a good string set.
The first player who becomes unable to perform the operation loses the game. Determine the winner of the game when both players play optimally.
Constraints
- , , ..., are all distinct.
- { , , ..., } is a good string set.
Input
Input is given from Standard Input in the following format:
Output
If Alice will win, print Alice
; if Bob will win, print Bob
.
Sample Input 1
2 2
00
01
Sample Output 1
Alice
If Alice adds 1
, Bob will be unable to add a new string.
Sample Input 2
2 2
00
11
Sample Output 2
Bob
There are two strings that Alice can add on the first turn: 01
and 10
. In case she adds 01
, if Bob add 10
, she will be unable to add a new string. Also, in case she adds 10
, if Bob add 01
, she will be unable to add a new string.
Sample Input 3
3 3
0
10
110
Sample Output 3
Alice
If Alice adds 111
, Bob will be unable to add a new string.
Sample Input 4
2 1
0
1
Sample Output 4
Bob
Alice is unable to add a new string on the first turn.
Sample Input 5
1 2
11
Sample Output 5
Alice
Sample Input 6
2 3
101
11
Sample Output 6
Bob