def exchange_elements(lst):
    from itertools import zip_longest, chain, tee
    
    lst1, lst2 = tee(iter(lst), 2)
    return list(chain.from_iterable(zip_longest(lst[1::2], lst[::2])))
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