Return the Index of the First Vowel

Create a function that returns the index of the first vowel in a string.

Examples

first_vowel("apple") ➞ 0

first_vowel("hello") ➞ 1

first_vowel("STRAWBERRY") ➞ 3

first_vowel("pInEaPPLe") ➞ 1

Notes

• Input will be single words.
• Characters in words will be upper or lower case.
• "y" is not considered a vowel.
• Input always contains a vowel.