start:
INBOX
COPYTO   0
INBOX
COPYTO   2
INBOX

main:
COPYTO   1
SUB      2
JUMPN    c0
COPYTO   1
ADD      2
COPYTO   2
SUB      1
COPYTO   1

c0:
COPYFROM 1
SUB      0
JUMPN    switch10
COPYFROM 0
OUTBOX
COPYFROM 1
OUTBOX
COPYFROM 2
OUTBOX
JUMP     start

switch10:
COPYTO   1
ADD      0
COPYTO   0
SUB      1
JUMP     main