7 1 83 9 9++ +18 7 3 15 1518 7 14 3 15 15 25 17 15 15

2 .3 5 .7 5 .2 .7 2 .3 5 .7 1 8

3 9 9

+

+ +

18 7 3 15 15

18 7 14 3 15 15 25 17 15 15