We define the usage of capitals in a word to be right when one of the following cases holds:

• All letters in this word are capitals, like "USA".
• All letters in this word are not capitals, like "leetcode".
• Only the first letter in this word is capital, like "Google".

Given a string word, return true if the usage of capitals in it is right.

• Input: word = "USA"
• Output: true

• Input: word = "FlaG"
• Output: false

• 1 <= word.length <= 100
• word consists of lowercase and uppercase English letters.