You are given an $m \times n$ binary matrix of $1$’s (representing soldiers) and $0$’s (representing civilians). The soldiers are positioned in front of the civilians, i.e., all the $1$’s will appear to the left of all the $0$’s in each row.

A row $i$ is weaker than a row $j$ if any of the following is TRUE:

• The number of soldiers in row $i$ is less than the number of soldiers in row $j$.

• Both rows have the same number of soldiers and $i \lt j$.

You have to return the indexes of the $k$ weakest rows in the matrix ordered from weakest to strongest.

Constraints:

• $m =$ matrix.length

• $n =$ matrix[i].length

• $2 \leq n, m \leq 100$

• $1 \leq k \leq m$

• matrix[i][j] is either $0$ or $1$.