Description

Input

The first line contains a single integer $t$ ($1 \le t \le 10^4$) — the number of testcases.

The first line of each testcase contains a single integer $m$ ($1 \le m \le 2 \cdot 10^5$) — the number of columns in the wall.

The $i$-th of the next two lines contains a string $c_i$, consisting of $m$ characters, where each character is either 'B' or 'W'. $c_{i, j}$ is 'B', if the cell $(i, j)$ should be colored black, and 'W', if the cell $(i, j)$ should be left white.

Additionally, for each $j$, the following constraint is satisfied: $c_{1, j}$, $c_{2, j}$ or both of them are equal to 'B'.

The sum of $m$ over all testcases doesn't exceed $2 \cdot 10^5$.

Output

For each testcase, print "YES" if Monocarp can paint a wall. Otherwise, print "NO".

6
3
WBB
BBW
1
B
B
5
BWBWB
BBBBB
2
BW
WB
5
BBBBW
BWBBB
6
BWBBWB
BBBBBB
 
 
 
 
 
 
 
 
 

YES
YES
NO
NO
NO
YES

Note

In the first testcase, Monocarp can follow a path $(2, 1)$, $(2, 2)$, $(1, 2)$, $(1, 3)$ with his brush. All black cells appear in the path exactly once, no white cells appear in the path.

In the second testcase, Monocarp can follow a path $(1, 1)$, $(2, 1)$.

In the third testcase:

• the path $(1, 1)$, $(2, 1)$, $(2, 2)$, $(2, 3)$, $(1, 3)$, $(2, 4)$, $(2, 5)$, $(1, 5)$ doesn't suffice because a pair of cells $(1, 3)$ and $(2, 4)$ doesn't share a common side;
• the path $(1, 1)$, $(2, 1)$, $(2, 2)$, $(2, 3)$, $(1, 3)$, $(2, 3)$, $(2, 4)$, $(2, 5)$, $(1, 5)$ doesn't suffice because cell $(2, 3)$ is visited twice;
• the path $(1, 1)$, $(2, 1)$, $(2, 2)$, $(2, 3)$, $(2, 4)$, $(2, 5)$, $(1, 5)$ doesn't suffice because a black cell $(1, 3)$ doesn't appear in the path;
• the path $(1, 1)$, $(2, 1)$, $(2, 2)$, $(2, 3)$, $(2, 4)$, $(2, 5)$, $(1, 5)$, $(1, 4)$, $(1, 3)$ doesn't suffice because a white cell $(1, 4)$ appears in the path.