A . 20 



2 . 7i{{/>o/i </(://)(r/ir/c/-i 

 2 . 7iu (//(>(/(' (//(>/>///eu,v 



3 . 7)i/</AKre /('/(//Kf/i/c 



4 ' 7>(f/o/nc i/e /7/f(/c' 



