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

int main() {
	int a, b;
	double ans;
	std::cin >> a >> b;

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

	if (a != b) {
		ans = std::sqrt(b*b - a*a);
	} else {
		ans = std::sqrt(b*b + a*a);
	}
	printf("%.10f\n", ans);
	return 0;
}