# 0500. Keyboard Row

https://leetcode.com/problems/keyboard-row

## Description

Given an array of strings `words`, return _the words that can be typed using letters of the alphabet on only one row of American keyboard like the image below_.

In the **American keyboard**:

* the first row consists of the characters `"qwertyuiop"`,
* the second row consists of the characters `"asdfghjkl"`, and
* the third row consists of the characters `"zxcvbnm"`.

![](https://assets.leetcode.com/uploads/2018/10/12/keyboard.png) **Example 1:**

```
**Input:** words = ["Hello","Alaska","Dad","Peace"]
**Output:** ["Alaska","Dad"]
```

**Example 2:**

```
**Input:** words = ["omk"]
**Output:** []
```

**Example 3:**

```
**Input:** words = ["adsdf","sfd"]
**Output:** ["adsdf","sfd"]
```

**Constraints:**

* `1 <= words.length <= 20`
* `1 <= words[i].length <= 100`
* `words[i]` consists of English letters (both lowercase and uppercase).

## ac

```java
```
