Triangle Counting

You are given n rods of length 1,2,...,n. You have to pick any 3 of them and build a triangle. How many distinct triangles can you make? Note that, two triangles will be considered different if they have at least 1 pair of arms with different length. Input The input for each case will have only a single positive integer n (3 ≤ n ≤ 1000000). The end of input will be indicated by a case with n < 3. This case should not be processed. Output For each test case, print the number of distinct triangles you can make. Sample Input 5 8 0 Sample Output 3 22