$1-$ Write a script file that uses any combination of the flow control commands to generate the following matrix. You must have nested loops and if statement in your codes.

$A=\left[\begin{array}{cccccc}1& 0& 3& 0& 0& 0\\ 0& 2& 0& 3& 0& 0\\ -1& 0& 3& 0& 3& 0\\ 0& -1& 0& 4& 0& 3\\ 0& 0& -1& 0& 5& 0\\ 0& 0& 0& -1& 0& 6\end{array}\right]$