#include <iostream>
#include <cstdint>
#include <cmath>
#include <iomanip>

using namespace std;

int main() {

  ios::sync_with_stdio(false);
  cin.tie(0);

  int a, b;
  cin >> a >> b;

  double ans1, ans2;
  ans1 = sqrt(a * a + b * b);
  if (a == b) {
    ans2 = sqrt(a * a + b * b);
  } else if (a > b) {
    ans2 = sqrt(a * a - b * b);
  } else {
    ans2 = sqrt(b * b - a * a);
  }

  cout << fixed << setprecision(6) << ((ans1 < ans2) ? ans1 : ans2) << endl;

  return 0;
}