#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;

typedef long long ll;
//typedef modint1000000007 mint;
const int MOD = 1000000007;
#define all(x) x.begin(), x.end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
const int inf = 1 << 30;
const ll INF = 1LL << 60;
const int dx[8] = {1, 0, -1, 0, -1, -1, 1, 1};
const int dy[8] = {0, 1, 0, -1, -1, 1, -1, 1};
template <class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template <class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }

bool ok(double a, double b, double c){
    if(c < a + b && abs(a - b) < c) return 1;
    else return 0;
}

int main(){
    cout << fixed << setprecision(10);
    double a, b;
    cin >> a >> b;

    vector<double> vec = {sqrt(a * a + b * b), sqrt(a * a - b * b), sqrt(b * b - a * a)};
    sort(all(vec));

    rep(i, 3){
        if(ok(a, b, vec[i])){
            cout << vec[i] << endl;
            return 0;
        }
    }

    return 0;
}