I'm trying to make the code scan for palindrome but I feel like something added in there that isn't needed. New to java so sorry if it make no sense

Question

// I'm looking for any errors or mistakes I made in the code or another way to do it with if-then statements or usage of array. (very new to java)

import java.util.Scanner;

public class Palindrome {

public static void main(String[] args) {

    Scanner input = new Scanner(System.in);
    System.out.println("Enter a string");
    String letter = input.nextLine();
    int n = letter.length();
    int numberOfLetters = 0;
    for (int i = 0; i < letter.length(); i++) {
        numberOfLetters++;
    }
    if(letter.charAt(0) != letter.charAt(n-1)){
       String letter2 = letter.toLowerCase();

   if (letter2.charAt(0) == letter2.charAt(n - 1)) {
            System.out.println("This is a palindrome " + letter);
        }
    else {
       System.out.println("This is not a palindrome " + letter);
   }

    }
}

}