@1
MOV UP, DOWN

@2
MOV UP, ACC
JEZ W
SUB 999
W: MOV ACC, DOWN

@3
MOV UP, ACC
JEZ W
SUB 999
W: MOV ACC, RIGHT

@4
MOV RIGHT, NIL
MOV 2, RIGHT
A: MOV LEFT, ACC
L: SAV
SUB RIGHT
JGZ B
SWP
MOV ACC, DOWN
ADD 2
MOV ACC, RIGHT
JMP A
B: MOV 1, RIGHT
SWP
JMP L

@5
L: MOV ACC, LEFT
JRO LEFT
E: MOV ACC, DOWN
S: MOV UP, ACC

@8
MOV ANY, ACC
JEZ Z
ADD 999
Z: MOV ACC, DOWN
