mark='mark';
for j=1:1:5000;
    if rand < .5;
        a(j)=1;
    else
       a(j)=0;
    end
    if rand > .5;
        b(j)=1;
    else
        b(j)=0;
    end
    if b(j) == a(j);
        c(j) = 0;
    else
        c(j) = 1;
    end
end
mark
1
for j=3:3:15000;
        d(j)=a(j/3);
        d(j+1)=b(j/3);
        d(j+2)=c(j/3);        
end
mark
2