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Maximum Number of Vowels in a Substring of Given Length

Problem Statement

Given a string s and an integer k, return the maximum number of vowel letters in any substring of s with length k.

Vowel letters in English are: 'a', 'e', 'i', 'o', and 'u'.

Examples

Example 1

Input:

s = "abciiidef", k = 3

Output:

3

Explanation: The substring "iii" contains 3 vowel letters.

Example 2

Input:

s = "aeiou", k = 2

Output:

2

Explanation: Any substring of length 2 contains exactly 2 vowels.

Example 3

Input:

s = "leetcode", k = 3

Output:

2

Explanation: The substrings "lee", "eet", and "ode" contain 2 vowels.

Constraints

• 1 <= s.length <= 10^5
• s consists of lowercase English letters.
• 1 <= k <= s.length