import java.awt.Color;
import acm.graphics.GLabel;
import acm.graphics.GRect;
import acm.program.GraphicsProgram;

public class Chess extends GraphicsProgram {

    String strZahlen[] = { "9", "8", "7", "6", "5", "4", "3", "2", "1" };
    String strBuchstaben[] = { "Z", "A", "B", "C", "D", "E", "F", "G", "H" };

    @Override
    public void run() {
        for (int greySquares = 0; greySquares <= 7; greySquares++) {
            if (greySquares % 2 != 0) {

                for (int gerade = 1; gerade <= 7; gerade += 2) {
                    for (int i1 = 0; i1 <= 3; i1++) {
                        GRect rectGrade = new GRect((100 + 100) * i1 + 100 + 100, gerade * 100, 100, 100);
                        rectGrade.setFilled(true);
                        rectGrade.setFillColor(Color.LIGHT_GRAY);
                        add(rectGrade);
                    }
                }

            } else {
                for (int ungerade = 2; ungerade <= 8; ungerade += 2) {
                    for (int i2 = 0; i2 <= 3; i2++) {
                        GRect rectUngerade = new GRect((100 + 100) * i2 + 100, ungerade * 100, 100, 100);
                        rectUngerade.setFilled(true);
                        rectUngerade.setFillColor(Color.LIGHT_GRAY);
                        add(rectUngerade);
                    }
                }
            }
        }
        for (int oben = 1; oben <= 8; oben++) {
            GLabel glabelOben = new GLabel(strBuchstaben[oben], 100 * oben + 45, 80);
            glabelOben.setFont("SansSerif-30");
            add(glabelOben);
        }
        for (int rechts = 1; rechts <= 8; rechts++) {
            GLabel glabelRechts = new GLabel(strZahlen[rechts], 925, 100 * rechts + 55);
            glabelRechts.setFont("SansSerif-30");
            add(glabelRechts);

        }
        for (int unten = 1; unten <= 8; unten++) {
            GLabel glabelUnten = new GLabel(strBuchstaben[unten], 100 * unten + 45, 940);
            glabelUnten.setFont("SansSerif-30");
            add(glabelUnten);
        }
        for (int links = 1; links <= 8; links++) {
            GLabel glabelLinks = new GLabel(strZahlen[links], 70, 100 * links + 55);
            glabelLinks.setFont("SansSerif-30");
            add(glabelLinks);
        }

    }
}