import sys
sys.setrecursionlimit(10000000)
def input():
    return sys.stdin.readline()[:-1]
from bisect import *
from collections import *
from heapq import *
from math import *
from fractions import Fraction

N, K = map(int, input().split())
if N >= K*2-1:
    print('YES')
else:
    print('NO') import sys sys sys.setrecursionlimit(10000000) sys.setrecursionlimit sys setrecursionlimit 10000000 def input():
    return sys.stdin.readline()[:-1] input return sys.stdin.readline()[:-1] sys.stdin.readline()[:-1] sys.stdin.readline() sys.stdin.readline sys.stdin sys stdin readline :-1 -1 from bisect import * from collections import * from heapq import * from math import * from fractions import Fraction N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K if N >= K*2-1:
    print('YES')
else:
    print('NO') N >= K*2-1 N K*2-1 K*2 K 2 1 print('YES') print 'YES' print('NO') print 'NO' N, K = map(int, input().split()) map(int, input().split()) N K = map(int, input().split()) map(int, input().split()) K def input():
    return sys.stdin.readline()[:-1] def input():
    return sys.stdin.readline()[:-1] input
import sys
sys.setrecursionlimit(10000000)
def input():
    return sys.stdin.readline()[:-1]
from bisect import *
from collections import *
from heapq import *
from math import *
from fractions import Fraction

N, K = map(int, input().split())
if N >= K*2-1:
    print('YES')
else:
    print('NO')
