modmap

sub modmap (Int $x is copy, @rads) {
    gather {
        while $x and @rads {
            my $rad = @rads.shift;
            take $x % $rad;
            $x div= $rad;
        }
        take $x if $x;
    }
}

say modmap 2804985923338703271682399481743033703427656749129565173066, 256 xx *;