Exercise: palindrome

Write a function func isPalindrome(s string) bool that returns true if the string reads the same from left to right and from right to left. Letter case and spaces do not count.

• isPalindrome("Level") → true
• isPalindrome("hello") → false
• isPalindrome("А роза упала на лапу Азора") → true

Constraints: the string consists of Latin and Russian letters and spaces, with at least one letter; spaces may come at the start, at the end and several in a row.

Do not add extra imports unless the task says so explicitly.