On the way home, DragonFly has got an extraordinarily large apple. He would like to share it with his friends. Now he wants to get
as many pieces as possible with n cuts. But he cannot decide how to cut it, because the apple is rather delicious. Now he needs your help.

输入格式

Each line contains an integer n (0<= n <= 100000).
Input will be terminated by EOF.

输出格式

You should print the largest number of pieces by n cuts of each case .

样例输入

1
2
3

样例输出

2
4
8

N个平面可以把空间分成(n*n*n+5*n+6)/6份

#include<stdio.h>
#include<math.h>

int main()
{
    long long n;
    long long max;
    while(scanf("%lld",&n)!=EOF)
    {
        max=(n*n*n+5*n+6)/6;
        printf("%lld\n",max);
        }
    return 0;
}