-1

-1 c 1 . .
, ²
c
-1-16/25 -1-16/25 1 16, 25
-1-35/50 -1-70/120 1 35, 50
-1-70/120 -1-70/120 1 70, 95, 120
-1-150/240 -1-150/240 1 150, 185, 240

.