1.1 1.2 1.3 1.3 1.4 1.4 1.5 1.5 1.6 1.7 2.1 2.1 2.2 2.3 2.4 2.5 2.6 2.6 3.1 3.1 3.2 3.2 3.3 3.4 3.4 3.5 3.5