def merge_dictionaries_three(dict1,dict2, dict3):
    import collections as ct
    
    merged_dict = dict(ct.ChainMap({},dict1,dict2,dict3))
    return merged_dict
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