264\. Ugly Number II

Medium

An **ugly number** is a positive integer whose prime factors are limited to `2`, `3`, and `5`.

Given an integer `n`, return _the_ <code>n<sup>th</sup></code> _**ugly number**_.

**Example 1:**

**Input:** n = 10

**Output:** 12

**Explanation:** [1, 2, 3, 4, 5, 6, 8, 9, 10, 12] is the sequence of the first 10 ugly numbers. 

**Example 2:**

**Input:** n = 1

**Output:** 1

**Explanation:** 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5. 

**Constraints:**

*   `1 <= n <= 1690`