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Score : $150$ points

问题陈述

这个问题中11/22字符串的定义与问题C和E中的定义相同。

如果一个字符串$T$满足以下所有条件，则称其为11/22字符串：

• $|T|$是奇数。这里，$|T|$表示$T$的长度。
• 第1个到第$(\frac{|T|+1}{2} - 1)$个字符都是1。
• 第$(\frac{|T|+1}{2})$个字符是/。
• 第$(\frac{|T|+1}{2} + 1)$个到第$|T|$个字符都是2。

例如，11/22、111/222和/是11/22字符串，但1122、1/22、11/2222、22/11和//2/2/211不是。

给定一个由1、2和/组成的长度为$N$的字符串$S$，确定$S$是否是一个11/22字符串。

以上为大语言模型 kimi 翻译，仅供参考。

Problem Statement

The definition of an 11/22 string in this problem is the same as in Problems C and E.

A string $T$ is called an 11/22 string when it satisfies all of the following conditions:

• $|T|$ is odd. Here, $|T|$ denotes the length of $T$.
• The $1$-st through $(\frac{|T|+1}{2} - 1)$-th characters are all 1.
• The $(\frac{|T|+1}{2})$-th character is /.
• The $(\frac{|T|+1}{2} + 1)$-th through $|T|$-th characters are all 2.

For example, 11/22, 111/222, and / are 11/22 strings, but 1122, 1/22, 11/2222, 22/11, and //2/2/211 are not.

Given a string $S$ of length $N$ consisting of 1, 2, and /, determine whether $S$ is an 11/22 string.

Constraints

• $1 \leq N \leq 100$
• $S$ is a string of length $N$ consisting of 1, 2, and /.

Input

The input is given from Standard Input in the following format:

$N$

$S$

Output

If $S$ is an 11/22 string, print Yes; otherwise, print No.

Sample Input 1

5
11/22

Sample Output 1

Yes

11/22 satisfies the conditions for an 11/22 string in the problem statement.

Sample Input 2

1
/

Sample Output 2

Yes

/ satisfies the conditions for an 11/22 string.

Sample Input 3

4
1/22

Sample Output 3

No

1/22 does not satisfy the conditions for an 11/22 string.

Sample Input 4

5
22/11

Sample Output 4

No