#include<iostream>
#include<math.h>

using namespace std;

int main(){

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

   if(a==b){
      printf("%.10f\n", sqrt(a*a+b*b));
      return 0;
   }
   if(a>b) swap(a, b);
   printf("%.10f\n", min(sqrt(a*a+b*b), sqrt(b*b-a*a)));

   return 0;
}