def unique_Characters(str):
    
    for i in range(len(str)):
        for j in range(i + 1,len(str)): 
            if (str[i] == str[j]):
                return False;
    return True;
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