a=1;
b=3;
c=0;
if (a==1)
    c=a;
else
    c=b;
end

%lets form the fibbonacci sequence
fib(1)=1
fib(2)=1
for i=3:20
    fib(i)=fib(i-2)+fib(i-1);
    fib(i);
end


figure(87)
hold on
for j=1:10
    if mod(j,2)==0
        plot(j,1,'r*')
    else
        plot(j,1,'gd')
    end
end


%xmas tree
figure(3)
hold on
for i=1:10
    for j=-(10-i):(10-i)
       plot(j,i,'g*')
    end
end