: ● 500 () ● 300 ( ) ● 250 ● 150 ● 4 . ● ● ● ● ● 800 ● 150 : . . . . . . , . . . , , . 3-4 . , , . . , . . , , - . . . , 5. . . 10 . 10-15 . . . !