Given an integer n, return true if n is an ugly number. Ugly number is a positive number whose prime factors only include 2, 3, and/or 5. Example 1: Input: n = 6 Output: true Explanation: 6 = 2 × 3 Example 2: Input: n = 8 Output: true Explanation: 8 = 2 × 2 × 2 Example 3: Input: n = 14 Output: false Explanation: 14 is not ugly since it includes another prime factor 7. Example 4: Input: n = 1 Output: true Explanation: 1 is typically treated as an ugly number. Constraints: -231 <= n <= 231 - 1