In how many distinct ways can you climb n stairs if you can take 1 or 2 steps at a time?
Example 1
Input: n = 2
Output: 2
Explanation: Two ways: 1+1 or 2.
Output: 2
Explanation: Two ways: 1+1 or 2.
Example 2
Input: n = 5
Output: 8
Explanation: The number of ways grows like Fibonacci numbers.
Output: 8
Explanation: The number of ways grows like Fibonacci numbers.