@4
MOV 0, RIGHT
MOV 1, RIGHT
MOV 2, RIGHT
MOV 3, RIGHT

@5
MOV 30, ACC
L: MOV LEFT, DOWN
SUB 1
JNZ L
MOV 30, ACC
M: SWP
MOV LEFT, ACC
SUB 3
NEG
MOV ACC, DOWN
SWP
SUB 1
JNZ M
MOV LEFT, NIL
MOV LEFT, NIL

@9
MOV 0, DOWN
SWP
MOV ACC, DOWN
ADD 1
SWP
MOV 30, ACC
L: MOV UP, DOWN
SUB 1
JNZ L
MOV -1, DOWN
