#include<iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<iomanip>

int main() {
	int a, b;

	std::cin >> a >> b;

	if (a > b) std::swap(a, b);

	std::cout << std::fixed << std::setprecision(10) << std::sqrt(b*b - a*a) << std::endl;
	return 0;
}