CF630F.Selection of Personnel

One company of IT City decided to create a group of innovative developments consisting from 5 to 7 people and hire new employees for it. After placing an advertisment the company received n resumes. Now the HR department has to evaluate each possible group composition and select one of them. Your task is to count the number of variants of group composition to evaluate.

IT City 的一家公司决定组建一个由 5 至 7 人组成的创新研发小组，并为此招聘新员工。在发布招聘广告后，该公司收到了 $n$ 份简历。目前，人力资源部门需要评估每一种可能的小组构成方案，并从中选出一种。你的任务是计算需要评估的小组构成方案总数。

The only line of the input contains one integer n (7 ≤ n ≤ 777) — the number of potential employees that sent resumes.

输入仅包含一行，其中有一个整数 $n$（$7 \leq n \leq 777$）——表示投递简历的潜在员工人数。

Output one integer — the number of different variants of group composition.

输出一个整数——即不同的分组方案数量。