#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
using namespace std;

// 行列の積
template <class T>
vector<vector<T> > matrixProduct(const vector<vector<T> >& x, const vector<vector<T> >& y)
{
    int a = x.size();
    int b = x[0].size();
    int c = y[0].size();
    vector<vector<T> > z(a, vector<T>(c, 0));
    for(int i=0; i<a; ++i){
        for(int j=0; j<c; ++j){
            for(int k=0; k<b; ++k){
                z[i][j] += x[i][k] * y[k][j];
            }
        }
    }
    return z;
}

// 行列の累乗
template <class T>
vector<vector<T> > matrixPower(const vector<vector<T> >& x, int k)
{
    int n = x.size();
    vector<vector<T> > y(n, vector<T>(n, 0));
    for(int i=0; i<n; ++i)
        y[i][i] = 1; // 積の単位元

    vector<vector<T> > z = x;
    while(k > 0){
        if(k & 1)
            y = matrixProduct(y, z);
        z = matrixProduct(z, z);
        k >>= 1;
    }
    return y;
}

int main()
{
    int p0, q;
    cin >> p0 >> q;

    vector<vector<double> > mat(102, vector<double>(102, 0.0));
    mat[101][101] = 1.0;
    for(int p=0; p<=100; ++p){
        mat[p][101]           +=        p  / 100.0 * (1.0 / 2.0) +
                                 (100 - p) / 100.0 * (1.0 / 3.0);
        mat[p][max(0,   p-q)] +=        p  / 100.0 * (1.0 / 2.0);
        mat[p][min(100, p+q)] += (100 - p) / 100.0 * (1.0 / 3.0);
    }

    mat = matrixPower(mat, 100000000);
    double ans = 1.0 / 3.0 * (1 + mat[p0][101]);
    printf("%.10f\n", ans);

    return 0;
}