$($Block Matrix$)$ In this problem, we will construct a matrix of a very particular form.

Specifically, it should look like $[$

I $0$

B I

$]$

where the size of B will be determined from keyboard input and will consist of random

integers between $0$ and $9.$ An example of a matrix of this form is

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$1000000$

$0100000$

$0010000$

$9761000$

$2190100$

$2040010$

$3070001$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

$$

block$\_$mat Function:

Input variables:

$$ none

Keyboard inputs$/$screen outputs:

$$ prompts the user for the number of rows and columns to be used in

constructing the matrix B

Output variables:

$$ the block matrix

A possible sample case is:

$>>$ A $=$ block$\_$mat$()$

Enter the number of rows for the block B: $4$

Enter the number of columns for the block B: $3$

A $=$

$1000000$

$0100000$

$0010000$

$9761000$

$2190100$

$2040010$

$3070001$

$4$