a,b = map(int,input().split())
# 判断是否为素数
def is_prime(num):
    for i in range(2,int(num**1/2)):
        if num % i == 0:
            return 0
    return 1
# 判断是否为回文数
def is_palindrome(num):
    s = str(num)
    if s == s[::-1]:
        return 1
    return 0

for i in range(a,b+1):
    if is_palindrome(i) and is_prime(i):
        print(i)