need help with Operating system problem.

8. (10 points) Consider the following program segments for two different processes executing concurrently, where a and b are not shared variables, but y is a shared variable with an initial value of 0. process 0: for a : 1 to 4 do y:= y + 8; process 1: for b := 1 to 4 do y:= y + 8; If these two processes execute only once at any speed, what are the possible resulting values of y? Explain your answers