CF937A.Olympiad

The recent All-Berland Olympiad in Informatics featured n participants with each scoring a certain amount of points.

As the head of the programming committee, you are to determine the set of participants to be awarded with diplomas with respect to the following criteria:

• At least one participant should get a diploma.
• None of those with score equal to zero should get awarded.
• When someone is awarded, all participants with score not less than his score should also be awarded.

Determine the number of ways to choose a subset of participants that will receive the diplomas.

最近举办的全贝尔兰信息学奥林匹克竞赛共有 $n$ 名参赛者，每名参赛者获得了一定的分数。

作为编程委员会主席，你需要根据以下标准确定获得证书（diplomas）的参赛者集合：

• 至少有一名参赛者获得证书；
• 所有得分为零的参赛者均不得获奖；
• 若某位参赛者获奖，则所有得分不低于该参赛者得分的参赛者也必须获奖。

请确定选择获奖参赛者子集的方式总数。

The first line contains a single integer n (1 ≤ n ≤ 100) — the number of participants.

The next line contains a sequence of n integers _a_1, _a_2, ..., a__n (0 ≤ a__i ≤ 600) — participants' scores.

It's guaranteed that at least one participant has non-zero score.

第一行包含一个整数 $n$（$1 \leq n \leq 100$）—— 参赛者人数。

下一行包含 $n$ 个整数 $a_1, a_2, \dots, a_n$（$0 \leq a_i \leq 600$）—— 各参赛者的得分。

保证至少有一名参赛者的得分不为零。

Print a single integer — the desired number of ways.

输出一个整数——即所求的方案数。

There are three ways to choose a subset in sample case one.

1. Only participants with 3 points will get diplomas.
2. Participants with 2 or 3 points will get diplomas.
3. Everyone will get a diploma!

The only option in sample case two is to award everyone.

Note that in sample case three participants with zero scores cannot get anything.

在样例一中，有三种方式选择获奖子集：

1. 只有得分为 3 分的参赛者获得证书。
2. 得分为 2 分或 3 分的参赛者获得证书。
3. 所有人都获得证书！

在样例二中，唯一可行的方案是为所有人颁奖。

注意：在样例三中，得分为 0 分的参赛者无法获得任何奖项。