Using the MARIE computer assembly language, write a program that computes the following expression:

$z=(a*b)+(c*d).$ The computer will read in the input values $a,b,c,$ and $d$ from the keyboard, the final

result $($z$)$ has to be displayed. In addition, every time an input value is read in$,$ it must be validated by

checking that the input is a positive number. If it is positive display the number on the screen; otherwise

display zero and end the program. Remember that the MARIE instruction set does not have an instruction

to execute multiplication. The program must be tested in the MARIE simulator