**Time limit:**10.00 s**Memory limit:**512 MB

**Input**

The first input line contains an integer $t$: the number of test cases. Then there are $t$ test cases, described as follows:

First there is a line with two numbers, $n$ and $m$, which indicates the size of the maze: $n$ blocks tall and $m$ blocks wide.

Then there is a line with two numbers, $a$ and $b$, indicating the position of the entrance and exit, with $2 \le a \le m-1$, and $2 \le b \le m-1$. The entrance is in the top row, in column $a$, and the exit is in the bottom row, in column $b$.

Finally, there are $n$ lines, with $m$ characters on each row. The characters are either

`0`

or `1`

, indicating a block of empty space or a block of solid wall, respectively.All blocks on the perimeter of the maze are walls, with the exception of the entrance and exit, which are empty.

**Output**

Output $t$ lines, one per test case. For each test case, output

`YES`

if there is a way to navigate the stick through the maze from the entrance to the exit, and `NO`

otherwise.**Limits**

- $1 \le t \le 50$

- $3 \le n \le 30$

- $1 \le m \le 30$

**Example**

Here we have four test cases, the first one is illustrated above.

Input:

`4`

13 16

8 13

1111111011111111

1111111011110001

1111111011110001

1111111011110001

1111111011110001

1000000000000001

1000111011110111

1000111011110111

1000111011110111

1000000011110111

1000000011110111

1000000011110111

1111111111110111

13 16

8 13

1111111011111111

1111111011110001

1111111011110001

1111111011110001

1111111011110001

1000000000000001

1011111011110111

1011111011110111

1011111011110111

1011111011110111

1011111011110111

1000000011110111

1111111111110111

13 16

8 13

1111111011111111

1111111011111111

1111111011110001

1111111011110001

1111111011110001

1000000000000001

1000111011110111

1000111011110111

1000111011110111

1000000011110111

1000000011110111

1000000011110111

1111111111110111

1 3

2 2

101

Output:

`YES`

NO

NO

YES