#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include<map>
#include <iomanip>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>


using namespace std;
#define MAX_MOD 1000000007
#define REP(i,n) for(int i = 0;i < n;++i)
#define LONGINF 1000000000000000000
int main() {
	double a[2];
	cin >> a[0] >> a[1];
	if (a[0] < a[1]) swap(a[0], a[1]);
	double top = a[0], bot = 0;
	a[0] *= a[0];
	a[1] *= a[1];
	for (int i = 0;i < 100000;++i) {
		double mid = (top + bot) / 2;
		double hoge = mid;
		mid *= mid;
		if (a[1] + mid < a[0]) {
			bot = hoge;
		}
		else {
			top = hoge;
		}
	}
	if (a[0] != a[1]) {
		cout << fixed << setprecision(30) << bot;
	}
	else {
		cout << fixed << setprecision(30) << sqrt(a[0] + a[1]) << endl;
	}
return 0;
}