Climb Stairs
easy
1. You are given a number n, representing the number of stairs in a staircase. 2. You are on the 0th step and are required to climb to the top. 3. In one move, you are allowed to climb 1, 2 or 3 stairs. 4. You are required to print the number of different paths via which you can climb to the top.
Constraints
0 <= n <= 20
Format
Input
A number n
Output
A number representing the number of ways to climb the stairs from 0 to top.
Example
Sample Input
4
Sample Output
7
Question Video