" " (.) "c " (.) (.)
:
  . ./ 850
. ./ 850 ------------- --------------
:
  / 8*50
/ 8*50 ------------- --------------
:
  / 6*50
/ 6*50 ------------- --------------
:
  / 5*50
/ 5*50 ------------- --------------
:
  . ./ 5*50
. ./ 5*50 ------------- --------------
:
    / 5 * 25
/ 5 * 25 ------------- --------------
: [ 1 ]