empty-list
swap
read-num
{
        space
        3
        times #(list)
        left-cons
        "."
        catenate #(list+list)
    m6
    3
    range1
    map-show
    cartesian-product
    @1
    catenate #(list+list)
}
times #(eval)
    show-space
    words
b2
sort #(list,block)
unlines