using System;

namespace No419{
    public class Program{
        public static void Main(string[] args){
            var sr = new StreamReader();
            //---------------------------------
            var A = sr.Next<int>();
            var B = sr.Next<int>();

            if(A == B){
                Console.WriteLine(Math.Sqrt(A * A + B * B));
                return;
            }

            if(A < B){
                Ex.Swap(ref A, ref B);
            }

            Console.WriteLine(Math.Sqrt(A * A - B * B));

            //---------------------------------
        }
    }

    public class Ex{
        public static void Swap<T>(ref T left, ref T right){
            var tmp = left;
            left = right;
            right = tmp;
        }  
    }

    public class StreamReader{
        private readonly char[] _c = {' '};
        private int _index = -1;
        private string[] _input = new string[0];
        private readonly System.IO.StreamReader _sr = new System.IO.StreamReader(Console.OpenStandardInput());

        public T Next<T>(){
            if(_index == _input.Length - 1){
                _index = -1;
                while(true){
                    string rl = _sr.ReadLine();
                    if(rl == null){
                        if(typeof(T).IsClass) return default(T);
                        return (T)typeof(T).GetField("MinValue").GetValue(null);
                    }
                    if(rl != ""){
                        _input = rl.Split(_c, StringSplitOptions.RemoveEmptyEntries);
                        break;
                    }
                }
            }
            return (T)Convert.ChangeType(_input[++_index], typeof(T), System.Globalization.CultureInfo.InvariantCulture);
        }
    }
}