java matriz

package javaapplication3;
import java.util.Scanner;
public class JavaApplication3 {
    static Scanner $input = new Scanner(System.in);
    public static void main(String[] args) {
        p("Type the size you want to your map: ");
        int lines = 0;
        boolean done = true;
        while(done){
            lines = l();
            if(lines < 2){
                p("\nYou can't choose this number. Try again!");
            }
            else{
                done = false;
            }
        }
        p("\nGive me your map:");
        int rows = lines;
        int[][] map = new int[lines][rows];
        int counter = 0;
        int count = 0;
        while(counter < lines){
            while(count < rows){
                p("\n   Position " + counter + "," + count + ": ");
                map[counter][count] = $input.nextInt();
                count++;
            }
            counter++;
            count = 0;
        }
        int d = 0;
        lines = lines - 1;
        while(lines >= 0){
            d = d + map[lines][lines];
            lines--;
        }
        p("\n\nHere is the plus of your main diagonal: " + d + "\n");
    }

    public static void p(String stri){
        System.out.print(stri);
    }

    public static Integer l(){
        return $input.nextInt();
    }
}