proc putchar
  0xCFFFFFFFFFFFFFFD st8
endproc

proc getchar
  0xCFFFFFFFFFFFFFFE ld8
endproc

proc puts
  while dup ld8 0 == not do
    dup ld8 :putchar
    1 u+
  endwhile
  pop
endproc

proc newline
  10 :putchar
endproc

proc main
  :getchar
  dup :putchar
  while dup "1" ld8 == do
    dup :putchar
  endwhile
endproc