#include<iostream>
#include <math.h>
#include <string>
#include <iomanip>
using namespace std;

int main(){
	double a, b;
	cin >> a >> b ;
	if (a > b){
		cout << sqrt(a*a-b*b) << endl;
	}
	else if (a < b){
		cout << sqrt(b*b - a*a) << endl;
	}else{
		cout << a*sqrt(2) << endl;
	}
	



	return 0;
}