Row

题意翻译

## 题目描述 ### 读入一个字符串，只含有$01$两种字符，合法则输出"$Yes$",否则输出"$No$"。 ### 不合法情况 $1$.一个为$0$的字符两旁没有$1$。 $2$.一个为$1$的字符两旁还有$1$。 ## 输入输出格式 ### 输入格式 共两行。第一行为一个正整数$n$，表示字符串的长度。第二行为一个字符串。 ### 输出格式 共一行。为字符串是否合法，合法输出"$Yes$",否则输出"$No$"，判断方法如题目描述中所说。

题目描述

You're given a row with $ n $ chairs. We call a seating of people "maximal" if the two following conditions hold: 1. There are no neighbors adjacent to anyone seated. 2. It's impossible to seat one more person without violating the first rule. The seating is given as a string consisting of zeros and ones ( $ 0 $ means that the corresponding seat is empty, $ 1 $ — occupied). The goal is to determine whether this seating is "maximal". Note that the first and last seats are not adjacent (if $ n \ne 2 $ ).

输入输出格式

输入格式

The first line contains a single integer $ n $ ( $ 1 \leq n \leq 1000 $ ) — the number of chairs. The next line contains a string of $ n $ characters, each of them is either zero or one, describing the seating.

输出格式

Output "Yes" (without quotation marks) if the seating is "maximal". Otherwise print "No". You are allowed to print letters in whatever case you'd like (uppercase or lowercase).

输入输出样例

输入样例 #1

3
101

输出样例 #1

Yes

输入样例 #2

4
1011

输出样例 #2

No

输入样例 #3

5
10001

输出样例 #3

No

说明

In sample case one the given seating is maximal. In sample case two the person at chair three has a neighbour to the right. In sample case three it is possible to seat yet another person into chair three.