width=input('enter the width of the box')
height =input('enter the height of the box')
for ii = 1:height
    for jj=1:ii
        if mod(jj,2)==0
            fprintf('*')
        else
            fprintf('b')
        end
    end
    fprintf('\n')
    for jj =1 : width
        fprintf('x')
    end
    fprintf('\n')
end