1) select 2nd left in borderline (in game) and hit the representing button
2a) if not flower, the thing is clear, which map you play, 83% chance :)
2b) if flower, select 2nd left in top line, continue with 3)
3) 3 possibilities: star, flower, 10coins, 33% that you can continue!!

first sign: second sign:
source: https://github.com/wolxXx/m3map