The flag of Andorra is a vertical tricolor of blue, yellow and red, with a ratio of 7:10. The blue band is closest to the hoist and is two-fifths of the total width. The yellow band is one-third of the total width, in the middle. The red band is the remaining two-fifths of the flag and is adjacent to the fly.

Yeah, GPT-3 can't do basic maths (2/5 + 1/3 + 2/5 = 17/15 > 1). Yes, the outer stripes are actually two fifths wide, the middle stripe is just above them. I could've placed the stripes in the order they are described, but then the middle stripe wouldn't really be in the "middle" anymore.