from sys import stdin
import math
import re
import queue

input = stdin.readline

MOD = 1000000007
INF = 122337203685477580

def solve():
    N,K = map(int, input().split())
    if(K > N%2 + N/2):
        print("NO")
    else:
        print("YES")

    
if __name__ == '__main__':
    solve() from sys import stdin import math math import re re import queue queue input = stdin.readline input stdin.readline stdin readline MOD = 1000000007 MOD 1000000007 INF = 122337203685477580 INF 122337203685477580 def solve():
    N,K = map(int, input().split())
    if(K > N%2 + N/2):
        print("NO")
    else:
        print("YES")

     solve N,K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K if(K > N%2 + N/2):
        print("NO")
    else:
        print("YES")

     K > N%2 + N/2 K N%2 + N/2 N%2 N 2 N/2 N 2 print("NO") print "NO" print("YES") print "YES" if __name__ == '__main__':
    solve() __name__ == '__main__' __name__ '__main__' solve() solve INF = 122337203685477580 122337203685477580 INF def solve():
    N,K = map(int, input().split())
    if(K > N%2 + N/2):
        print("NO")
    else:
        print("YES")

     def solve():
    N,K = map(int, input().split())
    if(K > N%2 + N/2):
        print("NO")
    else:
        print("YES")

     solve MOD = 1000000007 1000000007 MOD input = stdin.readline stdin.readline input
from sys import stdin
import math
import re
import queue

input = stdin.readline

MOD = 1000000007
INF = 122337203685477580

def solve():
    N,K = map(int, input().split())
    if(K > N%2 + N/2):
        print("NO")
    else:
        print("YES")

    
if __name__ == '__main__':
    solve()
