func sedol(s) {

    die 'No vowels allowed' if (s ~~ /[AEIOU]/);
    die 'Invalid format'    if (s !~ /^[0-9B-DF-HJ-NP-TV-Z]{6}$/);

    const base36 = ((@(0..9) + @('A'..'Z')) ~Z @(0..35) -> flatten.to_h);
    const weights = [1, 3, 1, 7, 3, 9];

    var vs = [base36{ s.chars... }];
    var checksum = (vs ~Z* weights -> sum);
    var check_digit = ((10 - checksum%10) % 10);
    return (s + check_digit);
}

%w(
    710889
    B0YBKJ
    406566
    B0YBLH
    228276
    B0YBKL
    557910
    B0YBKR
    585284
    B0YBKT
    B00030
).each { |s|
    say sedol(s);
}