/* -*- coding: utf-8 -*-
 *
 * 419.cc: No.419 直角三角形 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int a, b;
  cin >> a >> b;

  double c;
  if (a == b) c = sqrt(2.0) * a;
  else c = sqrt((double)abs(a * a - b * b));
  printf("%.10lf\n", c);
  return 0;
}