lines
m:
    ":"
    show-space
    over
    read-num
    256
    1
    primes #(1: primes_below)
    6
    times #(list)
        tuck
        divmod
            pop2
            @4
        f2
    m4
    catenate #(elem+list)
        1
        pair
    m2
    fold-product
        product
    m1
    sort #(list)
    group
        last
    m1
    sum
    show-line