python递归代码错误，在用户输入的区间中查找回文素数

def is_prime(num):
    if num < 2:
        return False
    for i in range(2, int(num**0.5) + 1):
        if num % i == 0:
            return False
    return True

def is_palindrome(num):
    return str(num) == str(num)[::-1]

def find_palindrome_primes(start, end):
    palindrome_primes = []
    for num in range(start, end + 1):
        if is_prime(num) and is_palindrome(num):
            palindrome_primes.append(num)
    return palindrome_primes

start = int(input("请输入区间起始值："))
end = int(input("请输入区间结束值："))

result = find_palindrome_primes(start, end)
print("区间内的回文素数为：", result)