def slove():
    import sys
    input = sys.stdin.readline
    n, k = list(map(int, input().rstrip('\n').split()))
    print("YES" if (n + 2 - 1) // 2 >= k else "NO")


if __name__ == '__main__':
    slove() def slove():
    import sys
    input = sys.stdin.readline
    n, k = list(map(int, input().rstrip('\n').split()))
    print("YES" if (n + 2 - 1) // 2 >= k else "NO") slove import sys sys input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline n, k = list(map(int, input().rstrip('\n').split())) n list(map(int, input().rstrip('\n').split())) list map(int, input().rstrip('\n').split()) map int input().rstrip('\n').split() ().rstrip('\n').split ().rstrip('\n') ().rstrip () input rstrip '\n' split k print("YES" if (n + 2 - 1) // 2 >= k else "NO") print "YES" if (n + 2 - 1) // 2 >= k else "NO" (n + 2 - 1) // 2 >= k (n + 2 - 1) // 2 n + 2 - 1 n + 2 n 2 1 2 k "YES" "NO" if __name__ == '__main__':
    slove() __name__ == '__main__' __name__ '__main__' slove() slove def slove():
    import sys
    input = sys.stdin.readline
    n, k = list(map(int, input().rstrip('\n').split()))
    print("YES" if (n + 2 - 1) // 2 >= k else "NO") def slove():
    import sys
    input = sys.stdin.readline
    n, k = list(map(int, input().rstrip('\n').split()))
    print("YES" if (n + 2 - 1) // 2 >= k else "NO") slove
def slove():
    import sys
    input = sys.stdin.readline
    n, k = list(map(int, input().rstrip('\n').split()))
    print("YES" if (n + 2 - 1) // 2 >= k else "NO")


if __name__ == '__main__':
    slove()
