1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Four levels: - one - two - three - four 1. one 1. two 1. three 1. four 1) one - two 1) three - four - one - two 1. three 1) four