# 1544. Make The String Great

https://leetcode.com/problems/make-the-string-great

## Description

Given a string `s` of lower and upper case English letters.

A good string is a string which doesn't have **two adjacent characters** `s[i]` and `s[i + 1]` where:

* `0 <= i <= s.length - 2`
* `s[i]` is a lower-case letter and `s[i + 1]` is the same letter but in upper-case or **vice-versa**.

To make the string good, you can choose **two adjacent** characters that make the string bad and remove them. You can keep doing this until the string becomes good.

Return _the string_ after making it good. The answer is guaranteed to be unique under the given constraints.

**Notice** that an empty string is also good.

**Example 1:**

```

**Input:** s = "leEeetcode"
**Output:** "leetcode"
**Explanation:** In the first step, either you choose i = 1 or i = 2, both will result "leEeetcode" to be reduced to "leetcode".
```

**Example 2:**

```

**Input:** s = "abBAcC"
**Output:** ""
**Explanation:** We have many possible scenarios, and all lead to the same answer. For example:
"abBAcC" --> "aAcC" --> "cC" --> ""
"abBAcC" --> "abBA" --> "aA" --> ""
```

**Example 3:**

```

**Input:** s = "s"
**Output:** "s"
```

**Constraints:**

* `1 <= s.length <= 100`
* `s` contains only lower and upper case English letters.

## ac

```java
```
