#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <stdio.h>
#include <cstring>
#include <queue>
#include <stack>
#include <functional>
#include <math.h>
#include <iomanip>
using namespace std;
#define Would
#define you
const int INF = 999999999;
const int MOD = 1e9 + 7;
const double pi = 3.141592653589793238;

bool f(long long n) {
	while (n % 2 == 0) { n /= 2; }
	if (n == 1) { return 0; }
	return 1;
}

int main() {
	double a, b;
	cin >> a >> b;
	cout << setprecision(20) << sqrt((b*b) - (a*a)) << endl;
}