#include <iostream>
#include <iomanip>
#include <cstdint>
#include <cmath>

using namespace std;

int main()
{
	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	int16_t a, b;
	cin >> a >> b;

	if (a == b) cout << fixed << setprecision(10) << a * sqrt(2) << '\n';
	else if (a < b) cout << fixed << setprecision(10) << sqrt(static_cast<int32_t>(b) * b - static_cast<int32_t>(a) * a);
	else cout << fixed << setprecision(10) << sqrt(static_cast<int32_t>(a) * a - static_cast<int32_t>(b) * b) << '\n';

	return 0;
}