<h2><a href="https://leetcode.com/problems/climbing-stairs">Climbing Stairs</a></h2> <img src='https://img.shields.io/badge/Difficulty-Easy-brightgreen' alt='Difficulty: Easy' /><hr><p>You are climbing a staircase. It takes <code>n</code> steps to reach the top.</p>

<p>Each time you can either climb <code>1</code> or <code>2</code> steps. In how many distinct ways can you climb to the top?</p>

<p>&nbsp;</p>

<p><strong class="example">Example 1:</strong></p>

<pre>

<strong>Input:</strong> n = 2

<strong>Output:</strong> 2

<strong>Explanation:</strong> There are two ways to climb to the top.

1. 1 step + 1 step

2. 2 steps

</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>

<strong>Input:</strong> n = 3

<strong>Output:</strong> 3

<strong>Explanation:</strong> There are three ways to climb to the top.

1. 1 step + 1 step + 1 step

2. 1 step + 2 steps

3. 2 steps + 1 step

</pre>

<p>&nbsp;</p>

<p><strong>Constraints:</strong></p>

<ul>

<li><code>1 &lt;= n &lt;= 45</code></li>

</ul>