Climbing Stairs

You are climbing a staircase. It takes n steps to reach the top.

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

Example 1:

Input: n = 2
Output: 2
Explanation: There are two ways: 1+1 and 2.

Example 2:

Input: n = 3
Output: 3
Explanation: There are three ways: 1+1+1, 1+2, and 2+1.

Constraints:

• 1 <= n <= 45