mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    N, K = map(int, input().split())
    if K <= (N+1) // 2:
        print("YES")
    else:
        print("NO")


if __name__ == '__main__':
    main() mod = 1000000007 mod 1000000007 eps = 10**-9 eps 10**-9 10 -9 def main():
    import sys
    input = sys.stdin.readline

    N, K = map(int, input().split())
    if K <= (N+1) // 2:
        print("YES")
    else:
        print("NO") main import sys sys input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K if K <= (N+1) // 2:
        print("YES")
    else:
        print("NO") K <= (N+1) // 2 K (N+1) // 2 N+1 N 1 2 print("YES") print "YES" print("NO") print "NO" if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main mod = 1000000007 1000000007 mod eps = 10**-9 10**-9 eps def main():
    import sys
    input = sys.stdin.readline

    N, K = map(int, input().split())
    if K <= (N+1) // 2:
        print("YES")
    else:
        print("NO") def main():
    import sys
    input = sys.stdin.readline

    N, K = map(int, input().split())
    if K <= (N+1) // 2:
        print("YES")
    else:
        print("NO") main
mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    N, K = map(int, input().split())
    if K <= (N+1) // 2:
        print("YES")
    else:
        print("NO")


if __name__ == '__main__':
    main()
