I was actually thinking the top 3, which would make it a round 40 in the final if my calculations are correct.
18 x 2 = 36 (Top 2 Songs from all studio albums except Hemispheres)
36 + 1 = 37 (Top Song from Hemispheres)
37 + 3 = 40 (Top 3 from Consolations)
40 sounds good, especially with it being close to the band's 40th Anniversary!
-Marc.