user: Implement `String#parse_mana_cost`, which parses [Magic: the Gathering mana costs](http://mtgsalvation.gamepedia.com/Mana_cost) expressed as a string and returns a `Hash` with keys being kinds of mana, and values being the numbers.

Don't include any mana types equal to zero.

Format is:

* optionally natural number representing total amount of generic mana (use key `*`)
* optionally followed by any combination of `w`, `u`, `b`, `r`, `g` (case insensitive in input, return lower case in output), each representing one mana of specific color.

If case of Strings not following specified format, return `nil/null/None`.

Answer: {"fn_name": "parse_mana_cost", "inputs": [[""], ["0"], ["1"], ["4"], ["15"], ["2rr"], ["1wbg"], ["1WWU"], ["0r"], ["2x"], ["2R"], ["2\n"], ["\n2"], ["1b"], ["1bb"], ["1bbb"], ["1bg"], ["1bgu"], ["1br"], ["1brg"], ["1g"], ["1gg"], ["1ggg"], ["1ggu"], ["1ggw"], ["1gu"], ["1guu"], ["1gw"], ["1gwu"], ["1gww"], ["1r"], ["1rg"], ["1rgg"], ["1rgw"], ["1rr"], ["1rrr"], ["1rrw"], ["1rw"], ["1rwb"], ["1rwu"], ["1u"], ["1ub"], ["1ubr"], ["1ur"], ["1uu"], ["1uub"], ["1uur"], ["1uuu"], ["1w"], ["1wb"], ["1wbr"], ["1wu"], ["1wub"], ["1wubrg"], ["1ww"], ["1wwbb"], ["1wwu"], ["1wwuu"], ["1www"], ["2"], ["2b"], ["2bb"], ["2bbb"], ["2bbr"], ["2bbrr"], ["2bbrrgg"], ["2bg"], ["2bgg"], ["2bgu"], ["2bgw"], ["2br"], ["2brg"], ["2brr"], ["2g"], ["2gg"], ["2ggg"], ["2gggg"], ["2gguu"], ["2ggww"], ["2ggwwuu"], ["2gu"], ["2gub"], ["2gur"], ["2guu"], ["2gw"], ["2gwu"], ["2gww"], ["2r"], ["2rg"], ["2rgw"], ["2rrgg"], ["2rrggww"], ["2rrr"], ["2rrrg"], ["2rrww"], ["2rw"], ["2rwb"], ["2u"], ["2ub"], ["2ubr"], ["2ur"], ["2urg"], ["2urw"], ["2uu"], ["2uubb"], ["2uubbrr"], ["2uurr"], ["2uuu"], ["2uuuu"], ["2w"], ["2wb"], ["2wbg"], ["2wu"], ["2wub"], ["2wuu"], ["2wuub"], ["2ww"], ["2wwb"], ["2wwbb"], ["2wwuu"], ["2wwuubb"], ["2www"], ["3"], ["3b"], ["3bb"], ["3bbb"], ["3bbbb"], ["3bbg"], ["3bbr"], ["3bbrr"], ["3bg"], ["3bgu"], ["3bgw"], ["3br"], ["3brg"], ["3g"], ["3gg"], ["3ggg"], ["3gggg"], ["3ggw"], ["3ggww"], ["3gu"], ["3gub"], ["3gur"], ["3gw"], ["3gwu"], ["3gww"], ["3r"], ["3rg"], ["3rgg"], ["3rgw"], ["3rr"], ["3rrg"], ["3rrgg"], ["3rrr"], ["3rrrr"], ["3rw"], ["3rwb"], ["3rwu"], ["3rww"], ["3u"], ["3ub"], ["3ubb"], ["3ubr"], ["3ur"], ["3urg"], ["3urw"], ["3uu"], ["3uub"], ["3uubb"], ["3uuu"], ["3w"], ["3wb"], ["3wbb"], ["3wbg"], ["3wbr"], ["3wu"], ["3wub"], ["3wubrg"], ["3wuu"], ["3ww"], ["3wwbb"], ["3wwu"], ["3wwuu"], ["3www"], ["4b"], ["4bb"], ["4bbb"], ["4bbbb"], ["4bbgg"], ["4bbrr"], ["4bg"], ["4br"], ["4brg"], ["4brr"], ["4brrg"], ["4g"], ["4gg"], ["4ggg"], ["4gggg"], ["4ggww"], ["4gu"], ["4gub"], ["4gw"], ["4gwwu"], ["4r"], ["4rg"], ["4rggw"], ["4rgw"], ["4rr"], ["4rrg"], ["4rrgg"], ["4rrr"], ["4rrww"], ["4rw"], ["4rww"], ["4u"], ["4ub"], ["4ubbr"], ["4ubr"], ["4ur"], ["4uu"], ["4uuu"], ["4w"], ["4wb"], ["4wbb"], ["4wbg"], ["4wbr"], ["4wu"], ["4wub"], ["4wuub"], ["4ww"], ["4wwbb"], ["4wwu"], ["4www"], ["5"], ["5b"], ["5bb"], ["5bbb"], ["5bg"], ["5bgw"], ["5br"], ["5g"], ["5gg"], ["5ggg"], ["5gu"], ["5guu"], ["5gw"], ["5r"], ["5rg"], ["5rr"], ["5rrr"], ["5rw"], ["5u"], ["5ub"], ["5ubb"], ["5ur"], ["5urg"], ["5uu"], ["5uuu"], ["5uuuu"], ["5w"], ["5wb"], ["5wu"], ["5wub"], ["5ww"], ["5wwu"], ["5www"], ["6"], ["6b"], ["6bb"], ["6bbb"], ["6bg"], ["6br"], ["6g"], ["6gg"], ["6ggg"], ["6gw"], ["6r"], ["6rr"], ["6rrr"], ["6u"], ["6uu"], ["6uuu"], ["6w"], ["6ww"], ["6www"], ["7"], ["7b"], ["7bb"], ["7bbb"], ["7g"], ["7gg"], ["7ggg"], ["7r"], ["7rr"], ["7rrr"], ["7u"], ["7uu"], ["7uuu"], ["7w"], ["7ww"], ["7www"], ["8"], ["8b"], ["8bb"], ["8bbb"], ["8bbgg"], ["8g"], ["8gg"], ["8ggg"], ["8r"], ["8rr"], ["8uu"], ["8uuu"], ["8uuuu"], ["8ww"], ["9"], ["9b"], ["9r"], ["b"], ["bb"], ["bbb"], ["bbbb"], ["bbbbbbbbbbbbbbb"], ["bbgg"], ["bbr"], ["bbrr"], ["bbrrrgg"], ["bg"], ["bgg"], ["bgu"], ["bgw"], ["br"], ["brg"], ["brgw"], ["g"], ["gg"], ["ggg"], ["gggg"], ["ggggg"], ["gggggg"], ["gggggggg"], ["gggwww"], ["gguu"], ["ggw"], ["ggww"], ["ggwwwuu"], ["gu"], ["gur"], ["guu"], ["gw"], ["gwu"], ["gwub"], ["r"], ["rg"], ["rgw"], ["rgwu"], ["rr"], ["rrgg"], ["rrgggww"], ["rrr"], ["rrrr"], ["rw"], ["rwb"], ["u"], ["ub"], ["ubbr"], ["ubr"], ["ubrg"], ["ur"], ["urg"], ["urr"], ["urw"], ["uu"], ["uub"], ["uubb"], ["uubbbrr"], ["uur"], ["uuu"], ["uuuu"], ["w"], ["wb"], ["wbb"], ["wbg"], ["wu"], ["wub"], ["wubr"], ["wubrg"], ["wuu"], ["wuub"], ["ww"], ["wwbb"], ["wwuu"], ["wwuubbrrgg"], ["wwuuubb"], ["www"], ["wwww"]], "outputs": [[{}], [{}], [{"*": 1}], [{"*": 4}], [{"*": 15}], [{"*": 2, "r": 2}], [{"*": 1, "w": 1, "b": 1, "g": 1}], [{"*": 1, "w": 2, "u": 1}], [{"r": 1}], [null], [{"*": 2, "r": 1}], [null], [null], [{"*": 1, "b": 1}], [{"*": 1, "b": 2}], [{"*": 1, "b": 3}], [{"*": 1, "b": 1, "g": 1}], [{"*": 1, "u": 1, "b": 1, "g": 1}], [{"*": 1, "b": 1, "r": 1}], [{"*": 1, "b": 1, "r": 1, "g": 1}], [{"*": 1, "g": 1}], [{"*": 1, "g": 2}], [{"*": 1, "g": 3}], [{"*": 1, "u": 1, "g": 2}], [{"*": 1, "w": 1, "g": 2}], [{"*": 1, "u": 1, "g": 1}], [{"*": 1, "u": 2, "g": 1}], [{"*": 1, "w": 1, "g": 1}], [{"*": 1, "w": 1, "u": 1, "g": 1}], [{"*": 1, "w": 2, "g": 1}], [{"*": 1, "r": 1}], [{"*": 1, "r": 1, "g": 1}], [{"*": 1, "r": 1, "g": 2}], [{"*": 1, "w": 1, "r": 1, "g": 1}], [{"*": 1, "r": 2}], [{"*": 1, "r": 3}], [{"*": 1, "w": 1, "r": 2}], [{"*": 1, "w": 1, "r": 1}], [{"*": 1, "w": 1, "b": 1, "r": 1}], [{"*": 1, "w": 1, "u": 1, "r": 1}], [{"*": 1, "u": 1}], [{"*": 1, "u": 1, "b": 1}], [{"*": 1, "u": 1, "b": 1, "r": 1}], [{"*": 1, "u": 1, "r": 1}], [{"*": 1, "u": 2}], [{"*": 1, "u": 2, "b": 1}], [{"*": 1, "u": 2, "r": 1}], [{"*": 1, "u": 3}], [{"*": 1, "w": 1}], [{"*": 1, "w": 1, "b": 1}], [{"*": 1, "w": 1, "b": 1, "r": 1}], [{"*": 1, "w": 1, "u": 1}], [{"*": 1, "w": 1, "u": 1, "b": 1}], [{"*": 1, "w": 1, "u": 1, "b": 1, "r": 1, "g": 1}], [{"*": 1, "w": 2}], [{"*": 1, "w": 2, "b": 2}], [{"*": 1, "w": 2, "u": 1}], [{"*": 1, "w": 2, "u": 2}], [{"*": 1, "w": 3}], [{"*": 2}], [{"*": 2, "b": 1}], [{"*": 2, "b": 2}], [{"*": 2, "b": 3}], [{"*": 2, "b": 2, "r": 1}], [{"*": 2, "b": 2, "r": 2}], [{"*": 2, "b": 2, "r": 2, "g": 2}], [{"*": 2, "b": 1, "g": 1}], [{"*": 2, "b": 1, "g": 2}], [{"*": 2, "u": 1, "b": 1, "g": 1}], [{"*": 2, "w": 1, "b": 1, "g": 1}], [{"*": 2, "b": 1, "r": 1}], [{"*": 2, "b": 1, "r": 1, "g": 1}], [{"*": 2, "b": 1, "r": 2}], [{"*": 2, "g": 1}], [{"*": 2, "g": 2}], [{"*": 2, "g": 3}], [{"*": 2, "g": 4}], [{"*": 2, "u": 2, "g": 2}], [{"*": 2, "w": 2, "g": 2}], [{"*": 2, "w": 2, "u": 2, "g": 2}], [{"*": 2, "u": 1, "g": 1}], [{"*": 2, "u": 1, "b": 1, "g": 1}], [{"*": 2, "u": 1, "r": 1, "g": 1}], [{"*": 2, "u": 2, "g": 1}], [{"*": 2, "w": 1, "g": 1}], [{"*": 2, "w": 1, "u": 1, "g": 1}], [{"*": 2, "w": 2, "g": 1}], [{"*": 2, "r": 1}], [{"*": 2, "r": 1, "g": 1}], [{"*": 2, "w": 1, "r": 1, "g": 1}], [{"*": 2, "r": 2, "g": 2}], [{"*": 2, "w": 2, "r": 2, "g": 2}], [{"*": 2, "r": 3}], [{"*": 2, "r": 3, "g": 1}], [{"*": 2, "w": 2, "r": 2}], [{"*": 2, "w": 1, "r": 1}], [{"*": 2, "w": 1, "b": 1, "r": 1}], [{"*": 2, "u": 1}], [{"*": 2, "u": 1, "b": 1}], [{"*": 2, "u": 1, "b": 1, "r": 1}], [{"*": 2, "u": 1, "r": 1}], [{"*": 2, "u": 1, "r": 1, "g": 1}], [{"*": 2, "w": 1, "u": 1, "r": 1}], [{"*": 2, "u": 2}], [{"*": 2, "u": 2, "b": 2}], [{"*": 2, "u": 2, "b": 2, "r": 2}], [{"*": 2, "u": 2, "r": 2}], [{"*": 2, "u": 3}], [{"*": 2, "u": 4}], [{"*": 2, "w": 1}], [{"*": 2, "w": 1, "b": 1}], [{"*": 2, "w": 1, "b": 1, "g": 1}], [{"*": 2, "w": 1, "u": 1}], [{"*": 2, "w": 1, "u": 1, "b": 1}], [{"*": 2, "w": 1, "u": 2}], [{"*": 2, "w": 1, "u": 2, "b": 1}], [{"*": 2, "w": 2}], [{"*": 2, "w": 2, "b": 1}], [{"*": 2, "w": 2, "b": 2}], [{"*": 2, "w": 2, "u": 2}], [{"*": 2, "w": 2, "u": 2, "b": 2}], [{"*": 2, "w": 3}], [{"*": 3}], [{"*": 3, "b": 1}], [{"*": 3, "b": 2}], [{"*": 3, "b": 3}], [{"*": 3, "b": 4}], [{"*": 3, "b": 2, "g": 1}], [{"*": 3, "b": 2, "r": 1}], [{"*": 3, "b": 2, "r": 2}], [{"*": 3, "b": 1, "g": 1}], [{"*": 3, "u": 1, "b": 1, "g": 1}], [{"*": 3, "w": 1, "b": 1, "g": 1}], [{"*": 3, "b": 1, "r": 1}], [{"*": 3, "b": 1, "r": 1, "g": 1}], [{"*": 3, "g": 1}], [{"*": 3, "g": 2}], [{"*": 3, "g": 3}], [{"*": 3, "g": 4}], [{"*": 3, "w": 1, "g": 2}], [{"*": 3, "w": 2, "g": 2}], [{"*": 3, "u": 1, "g": 1}], [{"*": 3, "u": 1, "b": 1, "g": 1}], [{"*": 3, "u": 1, "r": 1, "g": 1}], [{"*": 3, "w": 1, "g": 1}], [{"*": 3, "w": 1, "u": 1, "g": 1}], [{"*": 3, "w": 2, "g": 1}], [{"*": 3, "r": 1}], [{"*": 3, "r": 1, "g": 1}], [{"*": 3, "r": 1, "g": 2}], [{"*": 3, "w": 1, "r": 1, "g": 1}], [{"*": 3, "r": 2}], [{"*": 3, "r": 2, "g": 1}], [{"*": 3, "r": 2, "g": 2}], [{"*": 3, "r": 3}], [{"*": 3, "r": 4}], [{"*": 3, "w": 1, "r": 1}], [{"*": 3, "w": 1, "b": 1, "r": 1}], [{"*": 3, "w": 1, "u": 1, "r": 1}], [{"*": 3, "w": 2, "r": 1}], [{"*": 3, "u": 1}], [{"*": 3, "u": 1, "b": 1}], [{"*": 3, "u": 1, "b": 2}], [{"*": 3, "u": 1, "b": 1, "r": 1}], [{"*": 3, "u": 1, "r": 1}], [{"*": 3, "u": 1, "r": 1, "g": 1}], [{"*": 3, "w": 1, "u": 1, "r": 1}], [{"*": 3, "u": 2}], [{"*": 3, "u": 2, "b": 1}], [{"*": 3, "u": 2, "b": 2}], [{"*": 3, "u": 3}], [{"*": 3, "w": 1}], [{"*": 3, "w": 1, "b": 1}], [{"*": 3, "w": 1, "b": 2}], [{"*": 3, "w": 1, "b": 1, "g": 1}], [{"*": 3, "w": 1, "b": 1, "r": 1}], [{"*": 3, "w": 1, "u": 1}], [{"*": 3, "w": 1, "u": 1, "b": 1}], [{"*": 3, "w": 1, "u": 1, "b": 1, "r": 1, "g": 1}], [{"*": 3, "w": 1, "u": 2}], [{"*": 3, "w": 2}], [{"*": 3, "w": 2, "b": 2}], [{"*": 3, "w": 2, "u": 1}], [{"*": 3, "w": 2, "u": 2}], [{"*": 3, "w": 3}], [{"*": 4, "b": 1}], [{"*": 4, "b": 2}], [{"*": 4, "b": 3}], [{"*": 4, "b": 4}], [{"*": 4, "b": 2, "g": 2}], [{"*": 4, "b": 2, "r": 2}], [{"*": 4, "b": 1, "g": 1}], [{"*": 4, "b": 1, "r": 1}], [{"*": 4, "b": 1, "r": 1, "g": 1}], [{"*": 4, "b": 1, "r": 2}], [{"*": 4, "b": 1, "r": 2, "g": 1}], [{"*": 4, "g": 1}], [{"*": 4, "g": 2}], [{"*": 4, "g": 3}], [{"*": 4, "g": 4}], [{"*": 4, "w": 2, "g": 2}], [{"*": 4, "u": 1, "g": 1}], [{"*": 4, "u": 1, "b": 1, "g": 1}], [{"*": 4, "w": 1, "g": 1}], [{"*": 4, "w": 2, "u": 1, "g": 1}], [{"*": 4, "r": 1}], [{"*": 4, "r": 1, "g": 1}], [{"*": 4, "w": 1, "r": 1, "g": 2}], [{"*": 4, "w": 1, "r": 1, "g": 1}], [{"*": 4, "r": 2}], [{"*": 4, "r": 2, "g": 1}], [{"*": 4, "r": 2, "g": 2}], [{"*": 4, "r": 3}], [{"*": 4, "w": 2, "r": 2}], [{"*": 4, "w": 1, "r": 1}], [{"*": 4, "w": 2, "r": 1}], [{"*": 4, "u": 1}], [{"*": 4, "u": 1, "b": 1}], [{"*": 4, "u": 1, "b": 2, "r": 1}], [{"*": 4, "u": 1, "b": 1, "r": 1}], [{"*": 4, "u": 1, "r": 1}], [{"*": 4, "u": 2}], [{"*": 4, "u": 3}], [{"*": 4, "w": 1}], [{"*": 4, "w": 1, "b": 1}], [{"*": 4, "w": 1, "b": 2}], [{"*": 4, "w": 1, "b": 1, "g": 1}], [{"*": 4, "w": 1, "b": 1, "r": 1}], [{"*": 4, "w": 1, "u": 1}], [{"*": 4, "w": 1, "u": 1, "b": 1}], [{"*": 4, "w": 1, "u": 2, "b": 1}], [{"*": 4, "w": 2}], [{"*": 4, "w": 2, "b": 2}], [{"*": 4, "w": 2, "u": 1}], [{"*": 4, "w": 3}], [{"*": 5}], [{"*": 5, "b": 1}], [{"*": 5, "b": 2}], [{"*": 5, "b": 3}], [{"*": 5, "b": 1, "g": 1}], [{"*": 5, "w": 1, "b": 1, "g": 1}], [{"*": 5, "b": 1, "r": 1}], [{"*": 5, "g": 1}], [{"*": 5, "g": 2}], [{"*": 5, "g": 3}], [{"*": 5, "u": 1, "g": 1}], [{"*": 5, "u": 2, "g": 1}], [{"*": 5, "w": 1, "g": 1}], [{"*": 5, "r": 1}], [{"*": 5, "r": 1, "g": 1}], [{"*": 5, "r": 2}], [{"*": 5, "r": 3}], [{"*": 5, "w": 1, "r": 1}], [{"*": 5, "u": 1}], [{"*": 5, "u": 1, "b": 1}], [{"*": 5, "u": 1, "b": 2}], [{"*": 5, "u": 1, "r": 1}], [{"*": 5, "u": 1, "r": 1, "g": 1}], [{"*": 5, "u": 2}], [{"*": 5, "u": 3}], [{"*": 5, "u": 4}], [{"*": 5, "w": 1}], [{"*": 5, "w": 1, "b": 1}], [{"*": 5, "w": 1, "u": 1}], [{"*": 5, "w": 1, "u": 1, "b": 1}], [{"*": 5, "w": 2}], [{"*": 5, "w": 2, "u": 1}], [{"*": 5, "w": 3}], [{"*": 6}], [{"*": 6, "b": 1}], [{"*": 6, "b": 2}], [{"*": 6, "b": 3}], [{"*": 6, "b": 1, "g": 1}], [{"*": 6, "b": 1, "r": 1}], [{"*": 6, "g": 1}], [{"*": 6, "g": 2}], [{"*": 6, "g": 3}], [{"*": 6, "w": 1, "g": 1}], [{"*": 6, "r": 1}], [{"*": 6, "r": 2}], [{"*": 6, "r": 3}], [{"*": 6, "u": 1}], [{"*": 6, "u": 2}], [{"*": 6, "u": 3}], [{"*": 6, "w": 1}], [{"*": 6, "w": 2}], [{"*": 6, "w": 3}], [{"*": 7}], [{"*": 7, "b": 1}], [{"*": 7, "b": 2}], [{"*": 7, "b": 3}], [{"*": 7, "g": 1}], [{"*": 7, "g": 2}], [{"*": 7, "g": 3}], [{"*": 7, "r": 1}], [{"*": 7, "r": 2}], [{"*": 7, "r": 3}], [{"*": 7, "u": 1}], [{"*": 7, "u": 2}], [{"*": 7, "u": 3}], [{"*": 7, "w": 1}], [{"*": 7, "w": 2}], [{"*": 7, "w": 3}], [{"*": 8}], [{"*": 8, "b": 1}], [{"*": 8, "b": 2}], [{"*": 8, "b": 3}], [{"*": 8, "b": 2, "g": 2}], [{"*": 8, "g": 1}], [{"*": 8, "g": 2}], [{"*": 8, "g": 3}], [{"*": 8, "r": 1}], [{"*": 8, "r": 2}], [{"*": 8, "u": 2}], [{"*": 8, "u": 3}], [{"*": 8, "u": 4}], [{"*": 8, "w": 2}], [{"*": 9}], [{"*": 9, "b": 1}], [{"*": 9, "r": 1}], [{"b": 1}], [{"b": 2}], [{"b": 3}], [{"b": 4}], [{"b": 15}], [{"b": 2, "g": 2}], [{"b": 2, "r": 1}], [{"b": 2, "r": 2}], [{"b": 2, "r": 3, "g": 2}], [{"b": 1, "g": 1}], [{"b": 1, "g": 2}], [{"u": 1, "b": 1, "g": 1}], [{"w": 1, "b": 1, "g": 1}], [{"b": 1, "r": 1}], [{"b": 1, "r": 1, "g": 1}], [{"w": 1, "b": 1, "r": 1, "g": 1}], [{"g": 1}], [{"g": 2}], [{"g": 3}], [{"g": 4}], [{"g": 5}], [{"g": 6}], [{"g": 8}], [{"w": 3, "g": 3}], [{"u": 2, "g": 2}], [{"w": 1, "g": 2}], [{"w": 2, "g": 2}], [{"w": 3, "u": 2, "g": 2}], [{"u": 1, "g": 1}], [{"u": 1, "r": 1, "g": 1}], [{"u": 2, "g": 1}], [{"w": 1, "g": 1}], [{"w": 1, "u": 1, "g": 1}], [{"w": 1, "u": 1, "b": 1, "g": 1}], [{"r": 1}], [{"r": 1, "g": 1}], [{"w": 1, "r": 1, "g": 1}], [{"w": 1, "u": 1, "r": 1, "g": 1}], [{"r": 2}], [{"r": 2, "g": 2}], [{"w": 2, "r": 2, "g": 3}], [{"r": 3}], [{"r": 4}], [{"w": 1, "r": 1}], [{"w": 1, "b": 1, "r": 1}], [{"u": 1}], [{"u": 1, "b": 1}], [{"u": 1, "b": 2, "r": 1}], [{"u": 1, "b": 1, "r": 1}], [{"u": 1, "b": 1, "r": 1, "g": 1}], [{"u": 1, "r": 1}], [{"u": 1, "r": 1, "g": 1}], [{"u": 1, "r": 2}], [{"w": 1, "u": 1, "r": 1}], [{"u": 2}], [{"u": 2, "b": 1}], [{"u": 2, "b": 2}], [{"u": 2, "b": 3, "r": 2}], [{"u": 2, "r": 1}], [{"u": 3}], [{"u": 4}], [{"w": 1}], [{"w": 1, "b": 1}], [{"w": 1, "b": 2}], [{"w": 1, "b": 1, "g": 1}], [{"w": 1, "u": 1}], [{"w": 1, "u": 1, "b": 1}], [{"w": 1, "u": 1, "b": 1, "r": 1}], [{"w": 1, "u": 1, "b": 1, "r": 1, "g": 1}], [{"w": 1, "u": 2}], [{"w": 1, "u": 2, "b": 1}], [{"w": 2}], [{"w": 2, "b": 2}], [{"w": 2, "u": 2}], [{"w": 2, "u": 2, "b": 2, "r": 2, "g": 2}], [{"w": 2, "u": 3, "b": 2}], [{"w": 3}], [{"w": 4}]]}