Wow, you've thought about this carefully, Africa. The first two lines lead on to the third, and help to fix this picture. I can see now that if you added a white to the left train, and a red to the right train, they would be the same length.
Answer from Tjan: 2dg+1b=2or
Tjan, you've written what's there... but there is a problem with what's there. Can you see it?
Anaïs:w+o+o = d+d+B
Well done Anaïs!