#include <algorithm>
#include <array>
#include <bitset>
#include <cmath>
#include <functional>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <string>
#include <vector>

#include <iomanip>
#define pv(val) cerr << #val << '=' << (val) << endl
#define pvn(name, val) cerr << name << '=' << (val) << endl
#define pl cerr << '@' << __LINE__ << endl

using namespace std;

using ll = int64_t;
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()

template <class T>
ostream &operator<<(ostream &os, vector<T> const &vec) {
    if (vec.empty()) {
        os << "{}";
    } else {
        os << '{';
        for (size_t i = 0; i < vec.size() - 1; i++) os << vec[i] << ", ";
        os << vec.back() << '}';
    }
    return os;
}

template <class T, size_t S>
ostream &operator<<(ostream &os, array<T, S> const &arr) {
    if (arr.empty()) {
        os << "{}";
    } else {
        os << '{';
        for (size_t i = 0; i < arr.size() - 1; i++) os << arr[i] << ", ";
        os << arr.back() << '}';
    }
    return os;
}

template <class T, class U>
ostream &operator<<(ostream &os, pair<T, U> const &p) {
    os << '(' << p.first << ", " << p.second << ')';
    return os;
}

namespace math {
ll gcd(ll u, ll v) {
    while (v != 0) {
        ll r = u % v;
        u = v;
        v = r;
    }
    return u;
}
ll lcm(ll m, ll n) {
    if ((0 == m) || (0 == n)) return 0;

    return ((m / math::gcd(m, n)) * n);
}
}  // namespace math

struct UnionFind {
    vector<ll> data;
    UnionFind(ll size) : data(size, -1) {}
    bool unionSet(ll x, ll y) {
        x = root(x);
        y = root(y);
        if (x != y) {
            if (data[y] < data[x]) swap(x, y);
            data[x] += data[y];
            data[y] = x;
        }
        return x != y;
    }
    bool findSet(ll x, ll y) { return root(x) == root(y); }
    ll root(ll x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
    ll size(ll x) { return -data[root(x)]; }
};

template <class T, class U>
pair<T, U> operator+(pair<T, U> const &a, pair<T, U> const &b) {
    return pair<T, U>(a.first + b.first, a.second + b.second);
}

template <class T, class U>
pair<T, U> operator-(pair<T, U> const &a, pair<T, U> const &b) {
    return pair<T, U>(a.first - b.first, a.second - b.second);
}

ll bound(function<bool(ll)> f, ll ng, ll ok) {
    while (abs(ng - ok) > 1) {
        ll mid = (ng + ok) / 2;
        if (f(mid))
            ok = mid;
        else
            ng = mid;
    }

    return ok;
}

bool goRight(vector<string> const &c, ll y) {
    rep(i, c[0].size()) if (c[y][i] == '#') return false;
    return true;
}

bool start(vector<string> const &c, int y, int sy, int sx, int dy, int dx) {
    vector<pair<ll, ll>> stk;
    stk.push_back({sy, sx});

    vector<vector<bool>> visited(c.size(), vector<bool>(c[0].size(), false));

    while (!stk.empty()) {
        auto const t = stk.back();
        stk.pop_back();
        if (t.first < 0 || t.first >= c.size() || t.second < 0 || t.second >= c[0].size())
            continue;
        if (c[t.first][t.second] == '#') continue;
        if(visited[t.first][t.second]) continue;

        visited[t.first][t.second] = true;

        if (t.first == y) return true;

        stk.push_back({t.first + dy, t.second});
        stk.push_back({t.first, t.second + dx});
    }
    
    return false;
}

double prob(ll const N, ll const K, ll const n) {
    if (n >= K)
        return 1.0;
    double const X = ceil(log2((double)K / n));
    return pow(0.5, X);
}

int main(void) {
    ll N, K;
    cin >> N >> K;

    double p = 0.0;
    for (ll n = 1; n <= N; n++)
        p += prob(N, K, n);
    p /= N;
    cout << setprecision(11);
    cout << p << endl;



    return 0;
}


Measured memory_bytes: 888