Problem

Write a function that takes a string s and returns the count of vowels (a, e, i, o, u) in it. The function should handle both uppercase and lowercase vowels.

Examples

Example 1:

Input: s = "Hello World"
Output: 3

Explanation: The vowels are 'e', 'o', and 'o'.

Example 2:

Input: s = "Python Programming"
Output: 4

Explanation: The vowels are 'o', 'o', 'a', and 'i'.

Constraints

• The input string s can be empty.
• The length of s will not exceed 1000 characters.