Matrix dimensions error while solving kalman filter example

Hi I want to solve the following example for kalman filter but when I run the codes, the following error occures. Can you please help me to correct the codes? Thank you

??? Error using ==> ss.ss at 208

The value of the "OutputName" property must be a string vector with as many entries as outputs. Type "ltiprops lti" from more information.

Error in ==> kalman_pitch at 12

Plant = ss(A,[B B],C,0,-1,'inputname',{'u' 'w'},'outputname','y');

The codes are:

A=[-0.2231 -0.5282 0;-0.0450 -0.4696 0;0 1 0];
B=[0.0843;-0.1033;0];
C=[1 0 0;0 1 0; 0 0 1];
D=[0;0;0];
[num,den]=ss2tf(A,B,C,D)

Plant = ss(A,[B B],C,0,-1,'inputname',{'u' 'w'},'outputname','y');