def check_char(string):
	import re  
	regex = r'^[a-z]$|^([a-z]).*\1$'
	 
	if(re.search(regex, string)): 
		return "Valid" 
	else: 
		return "Invalid" 
def is_not_prime(n):
    import math
    
    result = False
    for i in range(2,int(math.sqrt(n)) + 1):
        if n % i == 0:
            result = True
    return result