lines
m:
    ":"
    show-space
    over
    read-num
    256
    1
    primes #(1: primes_below)
        2dup
        divides
        {
            tuck
            /
            over
            2dup
            divides
            @5
            when
        }
        when
        pop
    m6
    catenate #(elem+list)
        1
        pair
    m2
    fold-product
        product
    m1
    sort #(list)
    group
        last
    m1
    sum
    show-line