#include<bits/stdc++.h>
#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/numeric/interval.hpp>
#include <boost/numeric/interval/io.hpp>
using namespace::std;
namespace mp = boost::multiprecision;
typedef mp::number<mp::cpp_dec_float<32,int64_t>> cfloat;
typedef mp::cpp_int cint;
typedef long long lint;
typedef long double ldouble;
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
#define rep(i, n) for(lint i = 0; i < (lint)(n); i++)
#define irep(i) for(lint i = 0;; i++)
#define irep1(i) for(lint i = 1;; i++)
#define irep2(i) for(lint i = 2;; i++)
#define rrep(i, n) for(lint i = (lint)(n-1); i >-1; i--)
#define repi(i,a,b) for(lint i=lint(a);i<lint(b);i++)
#define rep2(i,a,b,c) for(lint i=lint(a);i>lint(b);i+=c)
#define all(x) (x).begin(),(x).end()
#define sl(c) (('a')<=(c)&&(c)<=('z'))
#define ll(c) (('A')<=(c)&&(c)<=('Z'))
#define max3(a,b,c) max(a,max(b,c))
#define min3(a,b,c) min(a,min(b,c))
#define PI 3.141592653589793
#define cout (cout<<fixed<<setprecision(15))
#define makeupper(t) (transform(all(t),t.begin(),::toupper))
#define makelower(t) (transform(all(t),t.begin(),::tolower))
#define dist(x1,y1,x2,y2) (pow(pow(x2-x1,2)+pow(y2-y1,2),0.5))
#define NEXT_LINE string junk; getline(cin, junk);
#define output(v) do{rep(i,v.size())cout<<(i?" ":"")<<v[i];cout<<"\n";}while(0)
#define output2(v) rep(i,v.size()){rep(j,v[i].size()){cout<<(j?" ":"")<<v[i][j];}cout<<"\n";}
#define INF 1<<30
#define LINT_MAX 9223372036854775807
#define MOD 1000000007
vector<lint> dx={-1,1,0,0,1,1,-1,-1};
vector<lint> dy={0,0,-1,1,1,-1,1,-1};
vector<lint> operator+(const vector<lint>& v1,const vector<lint>& v2){
    vector<lint> v(v1.size()+v2.size(),0);
    rep(i,v1.size())v[i]=v1[i];
    rep(i,v2.size())v[i+v1.size()]=v2[i];
    return v;
}
inline lint sum(vector<lint> v){
    lint sum=0;
    rep(i,v.size())sum+=v[i];
    return sum;
}
inline string replace(string str, string before, std::string after) {
	string::size_type  Pos(str.find(before));
	while (Pos != std::string::npos) {
		str.replace(Pos, before.length(), after);
		Pos = str.find(before, Pos + after.length());
	}
	return str;
}
inline vector<string> split(string s, string delim) {
	vector<string> elems;
	s=replace(s, "#", "HASH");
	s=replace(s, delim,"#");
	stringstream ss(s);
	string item;
	while (getline(ss, item, '#')) {
		elems.push_back(replace(item, "HASH", "#"));
	}
	return elems;
}
inline vector<int> cross(vector<int> a, vector<int> b) {
    return { a[1] * b[2] - a[2] * b[1],a[2] * b[0] - a[0] * b[2],a[0] * b[1] - a[1] * b[0] };
}
inline lint GCD(lint a,lint b){return b?GCD(b,a%b):a;}
inline vector<lint> primeList(lint n) {
    vector<bool> p(n+1);
    vector<lint> list;
    repi(i,1, n+1)p[i] = true;
    repi(i,2,sqrt(n)+1) {
        if (p[i]) {
            repi(j,2,n/i+1) {
                p[i*j] = false;
            }
        }
    }
    repi(i, 2, n+1)if (p[i])list.push_back(i);
    return list;
}
inline bool isPrime(int num){
    if (num < 2) return false;
    else if (num == 2) return true;
    else if (num % 2 == 0) return false;
    double sqrtNum = sqrt(num);
    for (int i = 3; i <= sqrtNum; i += 2){
        if (num % i == 0)return false;
    }
    return true;
}
inline lint max(vector<lint> num){
    lint M=num[0];
    rep(i,num.size())M=max(M,num[i]);
    return M;
}
inline lint min(vector<lint> num){
    lint M=num[0];
    rep(i,num.size())M=min(M,num[i]);
    return M;
}
inline lint signal(lint val){
    if(val==0)return 0;
    else return val/abs(val);
}
struct IVector2{
    lint x,y;
};
struct IVector3{
    lint x,y,z;
};
struct UnionFind{
    public:
    vector<lint> parent;
    vector<lint> rank;
    vector<lint> diff;
    lint _s;
    UnionFind(lint size){
        _s=size;
        parent.resize(size);
        rep(i,size)parent[i]=i;
        rank.resize(size,0);
        diff.resize(size,0);
    }
    void unite(lint x,lint y,lint w){
        int xr=root(x);
        int yr=root(y);
        if(rank[xr]>rank[yr]){diff[xr]=w+weight(x);parent[xr]=yr;_s--;}
        else if(rank[xr]<rank[yr]){diff[yr]=w+weight(y);parent[yr]=xr;_s--;}
        else if(xr!=yr){
            diff[yr]=w+weight(y);
            parent[yr] = xr;
            rank[xr]++;
            _s--;
        }
    }
    lint root(lint x) {
        while(x!=parent[x]){
            x=parent[x];
        }
        return x;
    }
    bool same(lint x, lint y) {
        return root(x) == root(y);
    }
    lint size(){
        return _s;
    }
    lint weight(lint x){
        lint ans=0;
        while(x!=parent[x]){
            ans+=diff[x];
            x=parent[x];
        }
        return ans;
    }
    lint dif(lint x, lint y) {
        return weight(y) - weight(x);
    }
};
struct Tree{
    public:
    vector<vector<IVector2>> list;
    vec diff;
    Tree(lint n){
        list.resize(n);
        diff.resize(n,INF);
    }
    void unite(lint a,lint b,lint w){
        list[a].push_back(IVector2{b,w});
        list[b].push_back(IVector2{a,w});
    }
    void makeDiff(lint x,lint w){
        diff[x]=w;
        for(IVector2 v:list[x]){
            if(diff[x]+v.y<diff[v.x])makeDiff(v.x,diff[x]+v.y);
        }
    }
};
int main(void){
  int N,K,w,i,l;
  double keisu,ans,x;
  ans=0;
  scanf("%d %d",&N,&K);
  keisu=(double)1/N;
  for(i=1;i<=N;i++){
    if(i<K){
      x=((double)K)/i;
      w=ceil(log2(x));
      l=pow(2,w);
      ans=ans+keisu/l;
    }
    else{
      ans=ans+keisu;
    }
  }
  printf("%13.12lf",ans);
  return 0;
}


Measured memory_bytes: 256