#include <bits/stdc++.h>

using namespace std;

int main()
{
  int a, b;
  cin >> a >> b;
  // a^2 + b^2 = c^2
  if(a > b) swap(a, b);

  cout << fixed << setprecision(10);
  if(a == b) cout << sqrt(a * a + b * b) << endl;
  else cout << sqrt(b * b - a * a) << endl;
}