import times, strutils, sequtils, math, algorithm, tables, sets, lists, intsets
import critbits, future, strformat, deques,heapqueue
template `max=`(x,y) = x = max(x,y)
template `min=`(x,y) = x = min(x,y)
template `mod=`(x,y) = x = x mod y
template scan2 = (scan(), scan())
template scan3 = (scan(), scan())
let read* = iterator: string {.closure.} =
    while true: (for s in stdin.readLine.split: yield s)
proc scan(): int = read().parseInt
proc scanf(): float = read().parseFloat
proc toInt(c:char): int =
    return int(c) - int('0')




    
proc solve()=
  var
    a = scanf()
    b = scanf()
    c = scanf()
  if a==0 and b==0:
    if c==0:
      echo -1
    else:
      echo 0
  elif a==0:
    echo 1
    echo -c/b
  else:
    if a < 0:
      a = -a
      b = -b
      c = -c
    var d = b^2-4*a*c
    if d==0:
      echo 1
      echo -b/(2*a)
    elif d>0:
      echo 2
      var t = newseq[float]()
      if b>0:
        t.add((-b-sqrt(d))/(2*a))
        t.add(c/(t[0]*a))
      elif b<0:
        t.add((-b+sqrt(d))/(2*a))
        t.add(c/(t[0]*a))
      t.sort()
      
      echo t.join("\n")
    else:
      echo 0

  
solve()