#include "bits/stdc++.h"
using namespace std;

int main() {
	double A, B;
	cin >> A >> B;
	if (A == B) {
		printf("%.9f\n", (double)A * sqrt(2.0));
		return 0;
	}
	if (A > B) swap(A, B);
	printf("%.9f\n", sqrt(B * B - A * A));
}