global M
global Filler
if M(XX,YY)==0
 
    pause(0.01);
    M(XX,YY)=Filler;
    
    XX
    XX=XX+1;
    FillMe;
    XX=XX-2;
    FillMe;
    XX=XX+1;YY=YY+1;
    FillMe;
    YY=YY-2;
    FIllMe;
    YY=YY+1;
end