In the card game Magic: the Gathering there are five different colours, which represent loose affiliations of cards, White (
W), Blue (
U), Black (
B), Red (
R) and Green (
G). These are often arranged in a pentagon as follows:
W G U R B
Both in the lore of MtG as well as in many card mechanics, adjacent colours in this pentagon are usually considered allies, and non-adjacent (sort of opposite) colours are considered enemies.
In this challenge, you'll be given two colours and should determine their relationship.
You're given any two distinct characters from the set
BGRUW. You may take these as a two-character string, a string with a delimiter between the characters, two separate character values, two singleton strings, two integers representing their code points, or a list or set type containing two characters/strings/integers.
Your output should be one of two distinct and consistent values of your choice, one which indicates that the two colours are allies and one which indicates that they are enemies. One of those two values may be no output at all.
This is code-golf, so the shortest valid answer – measured in bytes – wins.
There are only 20 possible inputs, so I'll list them all.
WU UB BR RG GW UW BU RB GR WG
WB UR BG RW GU BW RU GB WR UG