Вывести на экран символы в определенном порядке

import java.util.Scanner;
import java.util.stream.IntStream;
 
public class Distinct {
    private static final char IN = 'B';
    private static final char OUT = 'A';
 
    public static void main(String[] args) {
        System.out.print("Input length: ");
        int length = new Scanner(System.in).nextInt();
 
        System.out.println(getSquare(length, OUT, IN));
    }
 
    private static String getSquare(int length, char out, char in) {
        StringBuilder sb = new StringBuilder(symbols(out, length * 2));
        sb.append("\n");
        for (int index = 1; index < length - 1; index++) {
            sb.append(out).append(symbols(in, (length - 1) * 2)).append(out).append("\n");
        }
        return sb.append(symbols(out, length * 2)).append("\n").toString();
    }
 
    private static String symbols(char symbols, int count) {
        return IntStream.rangeClosed(1, count).
                mapToObj(x -> String.valueOf(symbols)).
                reduce("", (x, y) -> x + y);
    }
}