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

int main() {
	int a, b,temp;
	double ans;
	cin >> a >> b;
	if (a == b) {
		ans = a*pow(2, 0.5);
		cout << fixed << setprecision(9) << ans << endl;
		return 0;
	}
	temp = max(a, b)*max(a, b) - min(a, b)*min(a, b);
	ans = pow(temp, 0.5);
	cout << fixed << setprecision(9) << ans << endl;
	return 0;
}