#include <bits/stdc++.h>
using namespace std;

int main() {
  double a,b;
  cin >> a >> b;
  if(a<b) swap(a,b);
  double c=a*a-b*b;
  if(c==0) c=a*a+b*b;
  printf("%.10f\n",sqrt(c));
  return 0;
}