def is_prime(n): if n <= 1: return False if n == 2: return True if n % 2 == 0: return False for i in range(3, int(n**0.5) + 1, 2): if n % i == 0: return False return True def reverse(n): return int(str(n)[::-1]) M, N = map(int, input().split()) absolute_primes = [i for i in range(M, N + 1) if is_prime(i) and is_prime(reverse(i))] if absolute_primes: print(','.join(map(str, absolute_primes))) else: print('No')