import scala.io.StdIn

object Main {
  def main(args: Array[String]): Unit = {
    val in = StdIn.readLine().split(" ").map(_.toInt)
    val A = in(0)
    val B = in(1)
    println(
      if (A == B)
        math.sqrt(A * A + B * B)
      else
        math.sqrt(math.abs(A * A - B * B))
    )
  }
}