Calculate the formula

Problem Description

You just need to calculate the sum of the formula: 1^2+3^2+5^2+……+ n ^2.

 

Input

In each case, there is an odd positive integer n.

 

Output

Print the sum. Make sure the sum will not exceed 2^31-1

 

Sample Input

3

 

Sample Output

10

 

用普通的做法会超时，只能用公式算n*(4*n*n-1)/3(其中n为第几个数)，还有题目明明说好结果在int范围内的，但是必须用__int64才能过，郁闷。。。

 

 #include <stdio.h>

 int main(){
     __int64 number;
     __int64 n;
     __int64 result;

     while(scanf("%I64d",&number)!=EOF){
         n=(number+)/;

         result=n*(*n*n-)/;
         printf("%I64d\n",result);

     }
     return ;
 }