Palindrome Game (easy version)
Contest: Codeforces Round 721 (Div. 2)
Difficulty rating: 1200
Tags: constructive algorithms, games

The only difference between the easy and hard versions is that the given string $$$s$$$ in the easy version is initially a palindrome, this condition is not always true for the hard version.

A palindrome is a string that reads the same left to right and right to left. For example, "101101" is a palindrome, while "0101" is not.

Alice and Bob are playing a game on a string $$$s$$$ (which is initially a palindrome in this version) of length $$$n$$$ consisting of the characters '0' and '1'. Both players take alternate turns with Alice going first.

In each turn, the player can perform one of the following operations:

1. Choose any $$$i$$$ ($$$1 \le i \le n$$$), where $$$s[i] =$$$ '0' and change $$$s[i]$$$ to '1'. Pay 1 dollar.
2. Reverse the whole string, pay 0 dollars. This operation is only allowed if the string is currently not a palindrome, and the last operation was not reverse. That is, if Alice reverses the string, then Bob can't reverse in the next move, and vice versa.

Reversing a string means reordering its letters from the last to the first. For example, "01001" becomes "10010" after reversing.

The game ends when every character of string becomes '1'. The player who spends minimum dollars till this point wins the game and it is a draw if both spend equal dollars. If both players play optimally, output whether Alice wins, Bob wins, or if it is a draw.

Input format:
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 10^3$$$). Then $$$t$$$ test cases follow.

The first line of each test case contains a single integer $$$n$$$ ($$$1 \le n \le 10^3$$$).

The second line of each test case contains the string $$$s$$$ of length $$$n$$$, consisting of the characters '0' and '1'. It is guaranteed that the string $$$s$$$ is a palindrome and contains at least one '0'.

Note that there is no limit on the sum of $$$n$$$ over test cases.

Output format:
For each test case print a single word in a new line:

- "ALICE", if Alice will win the game,
- "BOB", if Bob will win the game,
- "DRAW", if the game ends in a draw.

Constraints:
Time limit: 1.0 s
Memory limit: 256.0 MB

Note:
In the first test case of the example,

- in the $$$1$$$-st move Alice has to perform the $$$1$$$-st operation, since the string is currently a palindrome.
- in the $$$2$$$-nd move Bob reverses the string.
- in the $$$3$$$-rd move Alice again has to perform the $$$1$$$-st operation. All characters of the string are '1', game over.

Example input:
2
4
1001
1
0

Example output:
BOB
BOB

Editorial:
If the count of zeros in the string $$$s$$$ is even then Bob always win
Proof
• Bob can restrict Alice from performing operation $$$2$$$ by making string $$$s$$$ palindrome (if Alice changes $$$s[i]$$$ to '1' then Bob will change $$$s[n-i+1]$$$ to '1'). However, when the last '0' is remaining, Bob will reverse the string, eventually forcing Alice to perform the operation $$$1$$$. This way Alice will spend $$$2$$$ dollars more than Bob resulting in Bob's win.
Proof
• Alice will change $$$s[n/2]$$$ from '0' to '1' and play with the same strategy as Bob did in the above case. This way Bob will spend $$$1$$$ dollar more than Alice resulting in Alice's win.