state start

    return_if(`ln` < '0' or `ln` > '9')

    read_number()
    `dnSN`
    `[ ]n`
    `0SD`
    blink()
    `lo+so`
end

interrupt program_start
    # C: cache
    `0sc`
end

interrupt program_end
    `10an`
    `lop`
end

function print_array

    for '?' in `l0` to `lc` do 
        array_get('X', `l?`)
        `n[ ]n`
    end
    `10an`

end


function blink
    # N: number
    # D: depth

    # if we hit max depth
    if `lD` == 25 then 
        `LNstLDst`
        return 1
    end
    
    # check cache
    if `lN` < 1000000 then
        if array_get('C', `lNlD1000000*+`) > 0 then
            return array_get('C', `LNLD1000000*+`)
        end
    end


    # 0 case -- check 1 rock
    if `lN` == 0 then

        `1SN`
        `lD1+SD`
        blink()

    end
    # even digit case -- check split rock
    if `lNZ2%` == 0 then

        `lN`
        `10lNZ2/^`
        `~` # get top and bottom

        `SNSN`
        `lD1+dSDSD`

        blink()
        blink()
        `+`

    end
    # default case
    if `lNZ2%` != 0 and `lN` != 0 then

        `lN2024*SN`
        `lD1+SD`
        blink()

    end

    `s.`
    # cacheable
    if `lN` < 1000000 then
        array_set('C', `lNlD1000000*+`, `l.`)
    end

    `LNstLDst` # clear params

    return `l.`

end

function read_number
    read_number_start()
    read_number_end()
end

function read_number_start

    -1
    # ret _1 if not a digit
    return_if(`ln` < 48)
    return_if(`ln` > 57)
    `st`

    # throw the true digit onto the stack
    `ln48-`

    # inc i
    adjust_index(1)
    # recurse
    read_number_start()

end

function read_number_end

    # if we only have 1 item on stack (-1) we found no number, so return
    return_if(1 == `z`)
    
    # push entire number thing onto temporary stack
    `[STz0<.]ds.x`
    # multiply ten then pop and add repeatedly until done
    `0`
    `[LTd_1=qr10*+l.x]ds.x`
    # get rid of the extra -1
    `st`
    # decrement i so we reread the skipped char
    adjust_index(-1)

end