# coding=utf-8
''' The sum of the squares of the first ten natural numbers is,
1^2 + 2^2 + ... + 10^2 = 385
The square of the sum of the first ten natural numbers is,
(1 + 2 + ... + 10)^2 = 552 = 3025
Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025  385 = 2640.
Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum. '''

total = 0
num = []
for i in range(100): num.append(i + 1)
for i in range(100):
  for j in range(i + 1, 100):
    total += num[i] * num[j]
total *= 2
print total