Given the N*M binary matrix, 1 represents the healthy person, and 0 represents a patient affected by a coronavirus. The task is to check the minimum time required for all persons to get affected. A patient at [i, j] cell affects a person at cell [i, j-1], [i, j+1] [i+1, j] and [i-1, j] in one second.
Note: There will be at least one patient
1. The first line of the input contains a single integerT denoting the number of test cases. The description of T test cases follows.
2. The first line of each test case contains two space-separated integers N and M.
3. Next N lines contain M space-separated binary integers.
Output: For each test case, print the minimum time required to all persons affected by COVID19
1. 1 <= T <= 100 2. 1 <= N, M <= 100 3. 0 <= mat[i][j] <= 1