#include <bits/stdc++.h>

using namespace std;

#define REP(i,a,b) for(int i=a;i<(int)b;i++)
#define rep(i,n) REP(i,0,n)
#define all(c) (c).begin(), (c).end()
#define zero(a) memset(a, 0, sizeof a)
#define minus(a) memset(a, -1, sizeof a)
#define watch(a) { cout << #a << " = " << a << endl; }
template<class T1, class T2> inline bool minimize(T1 &a, T2 b) { return b < a && (a = b, 1); }
template<class T1, class T2> inline bool maximize(T1 &a, T2 b) { return a < b && (a = b, 1); }

typedef long long ll;
int const inf = 1<<29;

int main() {

  double cs[3]; cin >> cs[0] >> cs[1];
  sort(cs, cs + 2);
  cs[2] = sqrt(cs[1] * cs[1] - cs[0] * cs[0]);
  if(cs[2] + cs[0] > cs[1]) {
    printf("%.10f\n", cs[2]);
  }
  else {
    cs[2] = sqrt(cs[1] * cs[1] + cs[0] * cs[0]);
    printf("%.10f\n", cs[2]);
  }
  
  return 0;
}