class Solution {
    public boolean detectCapitalUse(String word) {
        int lower=0;
        for(char ch: word.toCharArray()){
            if(ch>=97 && ch<=122)
                lower++;
        }
        
        return word.charAt(0)<=90 ? lower == word.length()-1 || lower == 0 : lower == word.length();
    }
}