import java.util.*;

public class Main{
        public static void main(String[] args){
                try(Scanner sc = new Scanner(System.in)){
                        double a = sc.nextDouble(), b = sc.nextDouble();
                        if(a != b){
                                System.out.printf("%.10f\n", Math.sqrt(Math.abs(a * a - b * b)));
                        }else{
                                System.out.printf("%.10f\n", Math.sqrt(Math.abs(a * a + b * b)));
                        }
                }
        }
}