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A14157. Space Navigation

编程题 普及/提高-

题目描述

You were dreaming that you are traveling to a planet named Planetforces on your personal spaceship. Unfortunately, its piloting system was corrupted and now you need to fix it in order to reach Planetforces.

![](/uploads/acgo/image/34676680fcd9f08c_f7ce6b5ce9e4.jpeg)Space can be represented as the $XY$ plane. You are starting at point $(0, 0)$ , and Planetforces is located in point $(p_x, p_y)$ .

The piloting system of your spaceship follows its list of orders which can be represented as a string $s$ . The system reads $s$ from left to right. Suppose you are at point $(x, y)$ and current order is $s_i$ :

- if $s_i = \text{U}$ , you move to $(x, y + 1)$ ;
- if $s_i = \text{D}$ , you move to $(x, y - 1)$ ;
- if $s_i = \text{R}$ , you move to $(x + 1, y)$ ;
- if $s_i = \text{L}$ , you move to $(x - 1, y)$ .

Since string $s$ could be corrupted, there is a possibility that you won't reach Planetforces in the end. Fortunately, you can delete some orders from $s$ but you can't change their positions.

Can you delete several orders (possibly, zero) from $s$ in such a way, that you'll reach Planetforces after the system processes all orders?

输入格式

The first line contains a single integer $t$ ( $1 \le t \le 1000$ ) — the number of test cases.

Each test case consists of two lines. The first line in each test case contains two integers $p_x$ and $p_y$ ( $-10^5 \le p_x, p_y \le 10^5$ ; $(p_x, p_y) \neq (0, 0)$ ) — the coordinates of Planetforces $(p_x, p_y)$ .

The second line contains the string $s$ ( $1 \le |s| \le 10^5$ : $|s|$ is the length of string $s$ ) — the list of orders.

It is guaranteed that the sum of $|s|$ over all test cases does not exceed $10^5$ .

输出格式

For each test case, print "YES" if you can delete several orders (possibly, zero) from $s$ in such a way, that you'll reach Planetforces. Otherwise, print "NO". You can print each letter in any case (upper or lower).

输入输出样例

输入 #1
6
10 5
RRRRRRRRRRUUUUU
1 1
UDDDRLLL
-3 -5
LDLDLDDDR
1 2
LLLLUU
3 -2
RDULRLLDR
-1 6
RUDURUUUUR
输出 #1
YES
YES
YES
NO
YES
NO

说明/提示

In the first case, you don't need to modify $s$ , since the given $s$ will bring you to Planetforces.

In the second case, you can delete orders $s_2$ , $s_3$ , $s_4$ , $s_6$ , $s_7$ and $s_8$ , so $s$ becomes equal to "UR".

In the third test case, you have to delete order $s_9$ , otherwise, you won't finish in the position of Planetforces.
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