s$ = "0,  1,  2,  4,  6,  7,  8, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24," + _
     "25, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 38, 39"
print ExtractRange$( s$)
end

function ExtractRange$( range$)
    n = 1
    count = ItemCount( range$, ",")
    while n <= count
        startValue = val( word$( range$, n, ","))
        m = n + 1
        while m <= count
            nextValue = val( word$( range$, m, ","))
            if nextValue - startValue <> m - n then exit while
            m = m + 1
        wend
        if m - n > 2 then
            ExtractRange$ = ExtractRange$ + str$( startValue) + "-" + str$( startValue + m - n - 1) + ","
        else
            for i = n to m - 1
                ExtractRange$ = ExtractRange$ + str$( startValue + i - n) + ","
            next i
        end if
        n = m
    wend
    ExtractRange$ = left$( ExtractRange$, len( ExtractRange$) - 1)
end function

function ItemCount( list$, separator$)
    while word$( list$, ItemCount + 1, separator$) <> ""
        ItemCount = ItemCount + 1
    wend
end function