import sys
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0

n,k = map(int,readline().split())

if (n+1)//2 >= k:
    print("YES")
else:
    print("NO") import sys sys readline = sys.stdin.buffer.readline readline sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline def even(n): return 1 if n%2==0 else 0 even n n n,k = map(int,readline().split()) n map(int,readline().split()) map int readline().split() ().split () readline split k if (n+1)//2 >= k:
    print("YES")
else:
    print("NO") (n+1)//2 >= k (n+1)//2 n+1 n 1 2 k print("YES") print "YES" print("NO") print "NO" k = map(int,readline().split()) map(int,readline().split()) k def even(n): return 1 if n%2==0 else 0 def even(n): return 1 if n%2==0 else 0 even readline = sys.stdin.buffer.readline sys.stdin.buffer.readline readline n,k = map(int,readline().split()) map(int,readline().split()) n
import sys
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0

n,k = map(int,readline().split())

if (n+1)//2 >= k:
    print("YES")
else:
    print("NO")