#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <cmath>

using namespace std;

int main() {
	int a, b;
	cin >> a >> b;
	double c;
	if (a == b) {
		c = a * sqrt(2);
	} else {
		c = sqrt(abs(a*a - b*b));
	}

	printf("%.10f\n", c);
	return 0;
}