Climbing Stairs

You are climbing a staircase with n steps. Each move you can climb either 1 or 2 steps. In how many distinct ways can you reach the top?

Example 1

Input: n = 2
Output: 2
Explanation: 1+1, or 2.

Example 2

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

Constraints

• 1 <= n <= 45