Hopping Rabbit

A rabbit can jump one, two, or three steps at a time to reach the top. You have to count the number of ways a rabbit can reach the top.

Write a function solve that have the following parameter(s):
1.) n: an integer

Example Input:
There is an integer that shows the number of steps at a time to reach the top:
n = 3
The function will return,

These are the ways to reach the top:
1 step + 1 step + 1 step, 1 step + 2 step, and 3.

• The number of steps will be greater than or equal to 1 and less than or equal to 25.