: . . - – – , . , , , 20- , . . , , . . . : , , . "" , , ( . (McCallum), ) "" , (), ( ), , - ( , , ).
" /-1.": , ... ( .1, .13) 1 - 2 - ... 15 - 16 - 17 - 18 - 19 - -2 ... 48 - 49 - 50 - ( -2)
, ... ( .1, .13)