Nearest Vowel

Given a letter, created a function which returns the nearest vowel to the letter. If two vowels are equidistant to the given letter, return the earlier vowel.

Examples

nearest_vowel("b") ➞ "a"

nearest_vowel("s") ➞ "u"

nearest_vowel("c") ➞ "a"

nearest_vowel("i") ➞ "i"

Notes

• All letters will be given in lowercase.
• There will be no alphabet wrapping involved, meaning the closest vowel to "z" should return "u", not "a".