import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double a = sc.nextDouble();
    double b = sc.nextDouble();
    double m = Math.min(a, b);
    double M = Math.max(a, b);
    double ans = (double)Math.sqrt(M * M - m * m);
    if(m == M) ans = (double)Math.sqrt(2 * m * m);
    System.out.println(ans);
  }
}