| Do you know Minesweeper, the famous video game? The player is initially |
| presented with a grid of undifferentiated squares. Some randomly selected |
| squares, unknown to the player, are designated to contain mines. One square |
| can contain at most one mine. |
| |
| The game is played by revealing squares of the grid, typically by clicking |
| them. After that, a digit is revealed in the square, indicating the number of |
| adjacent squares (under 8-way connectivity, that is, if two squares share |
| either an edge or a corner, they are considered adjacent) that contain mines. |
| If this number is zero then the surrounding squares are automatically also |
| revealed. This process applies recursively and automatically every time a new |
| square with count zero is revealed. |
| |
| Now, given a Minesweeper situation, you need to check if it is possible that |
| such a situation can occur after **exactly** 1 click on the grid. Note that |
| the game is designed in such a way, that the first clicked square never |
| contains a mine. |
| |
|
|
| ## Input: |
|
|
| The first line contains a single integer **T**, **T** ≤ 20. |
| Then **T** test cases follow. |
| The first line of each test case contains two integers **n**, **m** which |
| indicate the size of the grid (**1 ≤ n ≤ 16, 1 ≤ m ≤ 32**). |
| **n** lines follow, each line contains **m** characters describing the situation of the grid. |
| The meaning of the characters are as follows: |
| x: the square is not revealed after the first click |
| 0 - 8: the number of mines that are adjacent to this square |
| |
|
|
| ## Output: |
|
|
| Output a single line containing 'Yes' if the situation is valid after 1 click, |
| and 'No' otherwise (quotes for clarity). |
|
|
|
|
