#!/usr/bin/python3
def palidrome_keys(d):
	def is_palidrome(s):
		s= str(s)
		return s == s[::-1]
	result = []
	for key, value in d.items():
		if isinstance(value, str) and value.isalnum() and is_palidrome(value):
			result.append(key)
	return result			

def main():
	my_dict ={
		'a':'radar',
		'b':'hello',
		'c':'12312',
		'd':'test1',
		'e':'noon',
		'f':'123a321'
	}
	keys= palidrome_keys(my_dict)
	print("Κλειδία με παλίδρομες αλφαριθμητικές τιμές", keys)
if __name__=="__main__":
	main()