Diamond

package org.example;

import java.util.*;


class Diamond {
    public static void main(String[] args) {
        char[] letter = {
                'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U',
                'V', 'W', 'X', 'Y', 'Z'};
        int letter_number = 0;

        Scanner scan = new Scanner(System.in);
        char user_letter_init = scan.next().charAt(0);
        char user_letter = Character.toUpperCase(user_letter_init);
        System.out.println();

        for (int i = 0; i < letter.length; i++) {

            if (letter[i] == user_letter) {
                letter_number = i;
                break;
            }
        }
        if (user_letter == letter[0]) {
            System.out.println("A");
        } else {

            for (int i = 1; i <= letter_number + 1; i++) {

                for (int k = letter_number + 1 - i; k >= 0; k--) {
                    if (k > 0) {
                        System.out.print(" ");
                    } else {
                        for (int m = 1; m <= i; m++) {
                            System.out.print(letter[i - 1] + " ");
                        }


                        System.out.println();
                    }
                }

            }


            int counter = letter_number;

            for (int i = 1; i <= letter_number + 1; i++) {

                for (int k = 1; k <= i; k++) {

                    System.out.print(" ");


                }

                counter--;

                for (int z = counter; z >= 0; z--) {

                    System.out.print(letter[counter] + " ");

                }

                System.out.println();
            }


        }
    }
}