.def a=r16
    .def b=r17
    .def c=r18

    init:
        ldi tmp, LOW(RAMEND)
        out SPL, tmp
        ldi tmp, HIGH(RAMEND)
        out SPH, tmp

    start:
        ldi a, 3
        ldi b, 7

    loop:
        cpi a, 0
        brlo end_while
        dec a
        dec b
        ldi c, a

        cpi b, 6
        brne end_loop
        sub a, b

    end_loop
        cpi b, 3
        brne loop
        dec a
        rjmp loop


    end_while:
        ret