object Main {
    def solve(n: Int, m: Int) = {
        if (n == m) math.sqrt(math.pow(m, 2) + math.pow(n, 2))
        else math.sqrt(math.abs(math.pow(n, 2) - math.pow(m, 2)))
    }
    val Array(a, b) = io.StdIn.readLine.split(" ")
    def main(args: Array[String]) = println(solve(a.toInt, b.toInt))
}