Burrrrp in Kotlin

Given a number n, return the sound of a burp with n letters r: "bu", then n letters r, then "p".

Example 1:

Input: n = 4
Output: "burrrrp"
Explanation: "bu", then 4 letters r, then "p". That's the burp in this lesson's title.

Example 2:

Input: n = 1
Output: "burp"
Explanation: The shortest burp has a single r.

Example 3:

Input: n = 7
Output: "burrrrrrrp"
Explanation: "bu", then 7 letters r, then "p".

Constraints:

• n is a whole number from 1 to 20.
• The result is all lowercase.