def lscan; gets.split.map(&:to_r); end a,b,c = lscan if a == 0 if b == 0 p -1 exit end p 1 printf "%.15f\n", -c/b exit end d = b*b-4*a*c z = -b/2/a if d < 0 p 0 elsif d == 0 p 1 printf "%.15f\n", z else p 2 printf "%.15f\n", z-Math.sqrt(d)/2/a printf "%.15f\n", z+Math.sqrt(d)/2/a end