#include <bits/stdc++.h>

using namespace std;

struct Initializer {
  Initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    cout << fixed << setprecision(15);
  }
} initializer;

int main() {
  double a, b;
  cin >> a >> b;
  if (a < b) swap(a, b);
  cout << (a * a - b * b > 0 ? sqrt(a * a - b * b) : hypot(a, b)) << endl;
}