please explain me in side comment how the code workinb in each line. and after running on the marie stimulator give me screen shot on running code thanks

Using the MARIE computer assembly language, write a program that computes the following expression: z=abc. The computer will read in the input values a, b, and c from the keyboard and the final result (z) have to be displayed. In addition, every time an input value is read in, it must be displayed on the screen. Remember that the instruction set does not have an instruction to execute multiplication. Note: If any of the input values a,b, and c is a negative numbers or a zero, then the result printed should be "0". Otherwise, the result of the multiplication must be printed. The program must be tested on MARIE simulator