Sorting seaweeds into classes

A field team has recorded the main pigment and the stored food of eight seaweeds. You will write a key that names the class, count the seaweeds of each class, and list the red ones. Then the program draws the counts.

The idea. Phycoerythrin and floridean starch mean a red alga. Fucoxanthin with laminarin or mannitol means a brown alga. Chlorophyll b with starch means a green alga.

Your tasks.

1. In algal_class, return "green", "brown" or "red".
2. Set counts to a dictionary of each class and the number of seaweeds in it.
3. Set red_ones to the names of the red seaweeds, in the order of the list.