#include <iostream>
#include <algorithm>
#include <vector>
#include <cstdio>
#include <cstdlib>
typedef long long ll;
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

double p0, q;

bool solve(){//取り出す順番の添字を返す
    // 0 gu- 1 tyki 2 pa-
    int pkamo = -1, pnegi = -1;
    int kamo = rand() % 3;
    int negi = rand() % 3;
    int waza = 0;
    double p;
    while(kamo == negi){
        pkamo = kamo, pnegi = negi;

        //kamoの今回の手は
        vector<int> vkamo;
        rep(i, 3){
            if(i != pkamo) vkamo.push_back(i);
        }
        int tmp = rand() % 2;
        kamo = vkamo[tmp];


        //negiが必勝法を使う確率を求める
        if(waza == 0){//hazimete
            p = p0;
        }else if(waza == 1){//前回使用
            p -= q;
            if(p < 0) p = 0;
        }else if(waza == 2){//前回使用していない
            p += q;
            if(p > 1) p = 1;
        }

        double nowp = rand() % 101;

        if(nowp <= p){//必勝しよう
            negi = (pkamo + 1) % 3;
            waza = 1;
        }else{//しない
            negi = rand() % 3;
            waza = 2;
        }
    }

    //判定
    // printf("%d %d\n", negi, kamo);
    if(negi == 0 && kamo == 1) return true;
    if(negi == 1 && kamo == 2) return true;
    if(negi == 2 && kamo == 0) return true;
    return false;
}

int main(void){
    cin >> p0 >> q;
    
    int win = 0;
    rep(i, 1000000){
        if(solve()) win++;
    }
    printf("%.9f\n", (double)win / 1000000.0);
    return 0;
}