/** 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. */
#include "0.hpp"

#define _max 100

int main()
{
  uu sum = 0; // 最终的和
  uu num[_max];
  for(int i = 0; i < _max; i++) num[i] = i + 1;
  for(int i = 0; i < _max; i++)
    for(int j = i + 1; j < _max; j++)
      sum += num[i] * num[j];
  
  sum *= 2;
  cout << sum << endl;
  return 0;
}