# 20. Valid Parentheses

## Easy

***

Given a string `s` containing just the characters `'('`, `')'`, `'{'`, `'}'`, `'['` and `']'`, determine if the input string is valid.

An input string is valid if:

1. Open brackets must be closed by the same type of brackets.
2. Open brackets must be closed in the correct order.

 

**Example 1:**

```
Input: s = "()"
Output: true
```

**Example 2:**

```
Input: s = "()[]{}"
Output: true
```

**Example 3:**

```
Input: s = "(]"
Output: false
```

 

**Constraints:**

* `1 <= s.length <= 104`
* `s` consists of parentheses only `'()[]{}'`.