Here’s a map, which I discovered right here:

Your problem is to four-color this map whereas minimizing your use of the fourth shade.

More particularly, shade the map with 4 colours so every area is a distinct shade from all of its neighboring areas. Your rating is the variety of areas coloured in your least-used shade.

For occasion, in the event you coloured the map purple, blue, inexperienced, and yellow, utilizing purple 30 instances, blue 28 instances, inexperienced 26 instances, and yellow 28 instances, your rating can be 26.

The lowest rating wins. Proofs that it’s not possible to realize a smaller rating are additionally welcome.

I’ve achieved a rating of

8

and I imagine that’s the lowest doable rating, however be at liberty to attempt to outdo me.