@1
MOV UP, RIGHT

@2
MOV LEFT, DOWN
MOV ACC, DOWN
MOV UP, DOWN
MOV ACC, DOWN
ADD 8

@5
S: MOV UP, ACC
SAV
SUB UP
JGZ SN
MOV -1, DOWN
MOV UP, DOWN
MOV UP, DOWN
JMP S
SN: MOV UP, NIL
MOV UP, NIL
SWP
MOV ACC, DOWN

@7
S: MOV UP, ACC
JGZ USE_N
MOV UP, ACC
SAV
SUB UP
JGZ Z
SWP
USE_N:
MOV ACC, DOWN
JMP S
Z:
MOV 0, DOWN
