using System;

namespace No425{
    public class Program{
        public static void Main(string[] args){
            var sr = new StreamReader();
            //---------------------------------
            var p0 = sr.Next<decimal>() / 100.0m;
            var q = sr.Next<decimal>() / 100.0m;

            var memo = new decimal[1001, 101].ToJaggedArray();
            Ex.Fill(memo, decimal.MinValue);

            Func<int, decimal, decimal> dfs = null;
            dfs = (cnt, p) =>{
                var i = (int)(p * 100m);
                //メモされていたらそれを返す
                if(memo[cnt][i] != decimal.MinValue) return memo[cnt][i];
                //1000回以上あいこだったらとりあえずなんか返す
                if(cnt >= 1000) return 0.114514810m;
                //必勝法で勝利
                var a = p / 2.0m;
                //必勝法であいこ
                var b = p / 2.0m * dfs(cnt + 1, Ex.Clamp(0.0m, p - q, 1.0m));
                //必勝法を使わずに勝利
                var c = (1 - p) / 3.0m;
                //必勝法を使わずにあいこ
                var d = (1 - p) / 3.0m * dfs(cnt + 1, Ex.Clamp(0.0m, p + q, 1.0m));
                //メモしながら返す
                return memo[cnt][i] = a + b + c + d;
            };

            Console.WriteLine((dfs(0, p0) + 1) / 3.0m);
            //---------------------------------
        }
    }

    public static class ExMethod{
        public static T[][] ToJaggedArray<T>(this T[,] src){
            var x = src.GetLength(1);
            var y = src.GetLength(0);
            var ret = new T[y][];

            for(var i = 0; i < y; i++){
                ret[i] = new T[x];
                for(var j = 0; j < x; j++){
                    ret[i][j] = src[i, j];
                }
            }

            return ret;
        } 
    }

    public class Ex{
        public static T Clamp<T>(T min, T src, T max) where T:IComparable<T>{
            if(src.CompareTo(max) > 0) return max;
            if(src.CompareTo(min) < 0) return min;
            return src;
        }

        public static void Fill<T>(T[] src, T val){
            for(var i = 0; i < src.Length; i++){
                src[i] = val;
            }
        }

        public static void Fill<T>(T[][] src, T val){
            for(var i = 0; i < src.Length; i++){
                Fill(src[i], val);
            }
        }
    }

    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);
        }
    }
}