def match_num(string):
    import re
    
    text = re.compile(r"^5")
    if text.match(string):
        return True
    else:
        return False
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