close all
clear
clc

axis([1 13 1 13]);
a=1

for i=3:1:10

    for j=3:1:10

        if isequal(a,0)
            rectangle('Position',[j i 1 1], 'FaceColor',[.800 .800 .800])
            a=1;
        else
            rectangle('Position',[j i 1 1], 'FaceColor',[0 0 0])
            a=0;
        end

    end

     if isequal(a,0)
            a=1;
     else
            a=0;
     end

end