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 to climb to the top:
1. 1 step + 1 step
2. 2 steps

Example 2

Input: n = 3
Output: 3
Explanation: 1. (1+1+1), 2. (1+2), 3. (2+1)

Constraints

• 1 <= n <= 45