def is_prime(x):
    if x < 2:
        return False
    if x == 2 or x == 3 or x == 5:
        return True
    if x % 2 == 0 or x % 3 == 0 or x % 5 == 0:
        return False
    prime_number = 7
    difference = 4
    while prime_number <= math.sqrt(x):
        if x % prime_number == 0:
            return False
        prime_number += difference
        difference = 6 - difference
    return True
p, k = map(int, input().split())
if not is_prime(p) or not 2 <= p <= 10 ** 6 or not 0 <= k <= p - 1:
    print(BufferError)
else:
    print("NO")