=500
= 250
=0.5
:
=400
=2
=
=4 .
=20
. 20 .
. – 10 , . 20
. , 1 , . .
, , , . .
. , , . , .
. , .
.
12 – 15 .
. , , . , , .
– , 7 – 8 .
, .
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