Help with this assignment.

Main
LDR R1, VALUE1
LDR R2, VALUE2
MOV R0, # 000000000000000

LOOP:
ADD R0, R0, R1
SUBS R2, R2, #1
BNE LOOP
MOV R3, R0
PROGRAM DATA
VALUE1 00000002
VALUE2 00000003
END

1.(a) Explain how this program operates.
(b) Dry run it putting values at each stage.
(c) How many times is the looping going to
be done?
(d)What controls the looping here?
(e) What does BNE mean and after how
many loops will its value be true?

The information to the question is just like this.