题目描述
Problem Description
Alice and Bob are playing a game again.
In front of them, there are $n$ stones arranged in a row, with two colors: red and blue.
Alice moves first, and each player, in their turn, chooses one end from which to take a stone. The player who first takes $k$ red stones loses the game.
Assuming both Alice and Bob are extremely intelligent, determine who will win the game.
Input Format
The first line contains two integers $n$ and $k$.
The next line contains a string of length $n$, consisting only of characters C and P, where C represents a red stone and P represents a blue stone.
Output Format
If Alice is guaranteed to win, output DA; otherwise, output NE.
Sample Input and Output
Sample Input #1
4 1
CCCP
Sample Output #1
DA
Sample Input #2
8 2
PCPPCCCC
Sample Output #2
DA
Sample Input #3
9 1
PPCPPCPPC
Sample Output #3
NE
Notes
Data Range
For all data, $1 \le k < n \le 350$, and there are at least $2k-1$ red stones.
| Subtask | Special Constraints | Score |
|---|---|---|
| 1 | $n \le 20$ | 10 |
| 2 | $n \le 50$ | 20 |
| 3 | None | 40 |
Notes
This problem is worth a total of 70 points.
This problem is translated from the Croatian Open Competition in Informatics 2021/2022 Contest #1 T2 Kamenčići.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分