object Main { import java.io.{BufferedReader, InputStream, InputStreamReader} import java.util.StringTokenizer import scala.reflect.ClassTag def main(args: Array[String]): Unit = { val out = new java.io.PrintWriter(System.out) new Main(out, new InputReader(System.in)).solve() out.flush() } private[this] val oj = System.getenv("MY_DEBUG") == null def DEBUG(f: => Unit): Unit = { if (!oj){ f } } def debug(as: Array[Boolean]): Unit = if (!oj){ debug(as.map(x => if(x) "1" else "0").mkString) } def debug(as: Array[Int]): Unit = if (!oj){ debug(as.mkString(" ")) } def debug(as: Array[Long]): Unit =if (!oj){ debug(as.mkString(" ")) } def debugDim(m: Array[Array[Int]]): Unit = if (!oj){ REP(m.length) { i => debug(m(i)) } } def debugDimFlip(m: Array[Array[Long]]): Unit = if (!oj){ REP(m(0).length) { j => REP(m.length) { i => System.err.print(m(i)(j)) System.err.print(" ") } System.err.println() } } def debug(s: => String): Unit = { if (!oj){ System.err.println(s) } } def isDebug[A](debug: => A, online: => A): A = { if (oj) online else debug } class InputReader(val stream: InputStream) { private[this] val reader = new BufferedReader(new InputStreamReader(stream), 32768) private[this] var tokenizer: StringTokenizer = _ private[this] def next(): String = { while (tokenizer == null || !tokenizer.hasMoreTokens) tokenizer = new StringTokenizer(reader.readLine) tokenizer.nextToken } def nextInt(): Int = Integer.parseInt(next()) def nextLong(): Long = java.lang.Long.parseLong(next()) def nextChar(): Char = next().charAt(0) def ni(): Int = nextInt() def nl(): Long = nextLong() def nc(): Char = nextChar() def ns(): String = next() def ns(n: Int): Array[Char] = ns().toCharArray def na(n: Int, offset: Int = 0): Array[Int] = map(n)(_ => ni() + offset) def na2(n: Int, offset: Int = 0): (Array[Int], Array[Int]) = { val A1, A2 = Array.ofDim[Int](n) REP(n) { i => A1(i) = ni() + offset A2(i) = ni() + offset } (A1, A2) } def nm(n: Int, m: Int): Array[Array[Int]] = { val A = Array.ofDim[Int](n, m) REP(n) { i => REP(m) { j => A(i)(j) = ni() } } A } def nal(n: Int): Array[Long] = map(n)(_ => nl()) def nm_c(n: Int, m: Int): Array[Array[Char]] = map(n) (_ => ns(m)) } def REP(n: Int, offset: Int = 0)(f: Int => Unit): Unit = { var i = offset val N = n + offset while(i < N) { f(i); i += 1 } } def REP_r(n: Int, offset: Int = 0)(f: Int => Unit): Unit = { var i = n - 1 + offset while(i >= offset) { f(i); i -= 1 } } def TO(from: Int, to: Int)(f: Int => Unit): Unit = { REP(to - from + 1, from)(f) } def map[@specialized A: ClassTag](n: Int, offset: Int = 0)(f: Int => A): Array[A] = { val res = Array.ofDim[A](n) REP(n)(i => res(i) = f(i + offset)) res } def sumL(as: Array[Int]): Long = { var s = 0L REP(as.length)(i => s += as(i)) s } def cumSum(as: Array[Int]): Array[Long] = { val cum = Array.ofDim[Long](as.length + 1) REP(as.length) { i => cum(i + 1) = cum(i) + as(i) } cum } } object Workspace { import Main._ import java.util.Arrays.sort import scala.collection.mutable import math.{abs, max, min} import mutable.ArrayBuffer } class Main(out: java.io.PrintWriter, sc: Main.InputReader) { import sc._ import Main._ import java.util.Arrays.sort import scala.collection.mutable import math.{abs, max, min} import mutable.ArrayBuffer import Workspace._ import Integer.signum import Math.sqrt // toIntとか+7とかするならvalにしろ final private[this] val MOD = 1000000007 def solve(): Unit = { solve2() match { case None => out.println(-1) case Some(ans) => out.println(ans.length) ans.foreach(a => out.println(f"$a%.15f")) } } def solve2(): Option[Seq[Double]] = { val a, b, c = ni() val inf = None val none = Some(Seq.empty[Double]) if (a == 0) { if (b == 0) { if (c == 0) inf // 無限 else none // 解なし } else { Some(Seq(-c.toDouble / b)) } } else { val v = b.toLong*b - 4.toLong*a*c if (v < 0) { none // 虚数 } else if (v == 0) { Some(Seq(-b.toDouble/(2*a))) } else { val n = sqrt(v) if (a > 0) { Some(Seq((-b.toDouble - n) / (2 * a), (-b.toDouble + n) / (2 * a))) } else { Some(Seq((-b.toDouble + n) / (2 * a), (-b.toDouble - n) / (2 * a))) } } } } }