package main

import (
	"fmt"
	"math"
)

func main() {
	var a, b float64
	fmt.Scan(&a, &b)
	if a > b {
		a, b = b, a
	}
	if a!=b {
		fmt.Println(math.Sqrt(b*b-a*a))
	}else{
		fmt.Println(math.Sqrt(b*b+a*a))
	}
}