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((A, B) match {
      case (a, b) if a == b => math.sqrt(a * a + b * b)
      case _ => math.sqrt(math.abs(A * A - B * B))
    })
  }
}