Oh sorry, it's not Myanmar. It's Thailand in the region. I somehow must've misclicked and not checked it afterwards. I've gone over the whole map again, there should be no other mistakes now...
Explanation for the graph:
A originates from land: Blue
A and B originate from land: Purple
B originates from land: Red
B and C originate from land: Orange
C originates from land: Yellow
C and A originate from land: Green
A and B and C originate from land: Brown
[EDIT: How do I phrase that correctly? "originates" from doesn't nail it completely... Probably "is present in"]
A,B and C are not the countries themselves, they are something inside (and outside) of them. I hope that's not clear.
EDIT: and no, not politics and not intergovernemental organizations.