# By default, the following code will be test by timeit function.
# If you want to test the code without using timeit function,
# just comment line 5 and line 68-72.

code="""

#==============================================
# The following code is used to give run time using datetime.now().
from datetime import datetime
start_time=datetime.now()
#==============================================

import math 

def divisors_sum(n):
    if n==1:
        return 0

    divisors=[1]

    if n%2==0:
        start_i=2
        step=1
    else:
        start_i=3
        step=2

    for i in range(start_i,int(math.sqrt(n)+1),step):
        if n%i==0:
            divisors.append(i)
            quotient=n//i
            if quotient!=i:
                divisors.append(quotient)

    return sum(divisors)


abundant_nums=[12]
for n in range(13,28123+1):
    if n<divisors_sum(n):
        abundant_nums.append(n)


abundant_products=set()
for i in range(len(abundant_nums)):
    for j in range(i,len(abundant_nums)):
        abundant_products.add(abundant_nums[i]+abundant_nums[j])
        

impracticable_nums=[]
for n in range(1,28123+1):
    if n not in abundant_products:
        impracticable_nums.append(n)

print('computational result:',sum(impracticable_nums))


#==============================================
# The following code is used to give run time using datetime.now().
end_time=datetime.now()
print()
print('start time:',start_time)
print('end time:',end_time)
print('duration:',end_time-start_time)
#==============================================


"""

import timeit
print('timeit:',timeit.timeit(code,number=1))