103640: [Atcoder]ABC364 A - Glutton Takahashi

Problem Statement

Takahashi is planning to eat $N$ dishes.

The $i$-th dish he plans to eat is sweet if $S_i =$ sweet, and salty if $S_i =$ salty.

If he eats two sweet dishes consecutively, he will feel sick and be unable to eat any more dishes.

Determine whether he can eat all the dishes.

Constraints

• $N$ is an integer between $1$ and $100$, inclusive.
• Each $S_i$ is sweet or salty.

Input

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

$N$
$S_1$
$S_2$
$\vdots$
$S_N$

Output

Print Yes if Takahashi can eat all the dishes, and No otherwise.

Sample Input 1

5
salty
sweet
salty
salty
sweet

Sample Output 1

Yes

He will not eat two sweet dishes consecutively, so he can eat all the dishes without feeling sick.

Sample Input 2

4
sweet
salty
sweet
sweet

Sample Output 2

Yes

He will feel sick but can still eat all the dishes.

Sample Input 3

6
salty
sweet
sweet
salty
sweet
sweet

Sample Output 3

No

He feels sick when eating the 3rd dish and cannot eat the 4th and subsequent dishes.

问题陈述

高桥计划吃N道菜。

如果他计划吃的第i道菜是甜的，那么$S_i =$ sweet，如果是咸的，那么$S_i =$ salty。

如果他连续吃两道甜菜，他会感到不舒服，并且无法再吃任何菜。

判断他是否可以吃掉所有的菜。

约束条件

• $N$是介于1到100（包含）之间的整数。
• 每个$S_i$是sweet或salty。

输入

输入从标准输入以下格式给出：

$N$
$S_1$
$S_2$
$\vdots$
$S_N$

输出

如果高桥可以吃掉所有的菜，打印Yes，否则打印No。

样本输入1

5
salty
sweet
salty
salty
sweet

样本输出1

Yes

他不会连续吃两道甜菜，所以他可以在不感到不舒服的情况下吃掉所有的菜。

样本输入2

4
sweet
salty
sweet
sweet

样本输出2

Yes

他会感到不舒服，但仍然可以吃掉所有的菜。

样本输入3

6
salty
sweet
sweet
salty
sweet
sweet

样本输出3

No

他在吃第3道菜时感到不舒服，无法吃第4道及以后的菜。