/******************
*  Author: BD747  *
******************/
/*


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*/
#include<algorithm>
#include<cstdio>
#include<iostream>
#include<cstring>
#include<cmath>
#include<map>
#include<queue>
#include<set>
#include<sstream>
#include<stack>
#include<string>
#include<vector>
#include<bits/stdc++.h>
using namespace std;

int main(){

    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int a,b;
    cin>>a>>b;
    if(b<=(a+1)/2){
        cout<<"YES"<<endl;
    }else{
        cout<<"NO"<<endl;
    }

    return 0;
}

Measured memory_bytes: 256