function err = KBtis(x)
%

F(1) = -1+(1-x(4))+(1-x(9))+x(1)-(1-x(4))*(1-x(9))-(1-x(4))*x(1)-(1-x(9))*x(1)+(1-x(4))*(1-x(9))*x(1);
F(2) = -1+(1-x(4))+(1-x(10))+x(1)-(1-x(4))*(1-x(10))-(1-x(4))*x(1)-(1-x(10))*x(1)+(1-x(4))*(1-x(10))*x(1);
F(3) = -1+(1-x(4))+(1-x(11))+x(1)-(1-x(4))*(1-x(11))-(1-x(4))*x(1)-(1-x(11))*x(1)+(1-x(4))*(1-x(11))*x(1);
F(4) = -1+(1-x(4))+(1-x(12))+x(1)-(1-x(4))*(1-x(12))-(1-x(4))*x(1)-(1-x(12))*x(1)+(1-x(4))*(1-x(12))*x(1);
F(5) = -1+(1-x(4))+(1-x(13))+x(3)-(1-x(4))*(1-x(13))-(1-x(4))*x(3)-(1-x(13))*x(3)+(1-x(4))*(1-x(13))*x(3);
F(6) = -1+(1-x(5))+(1-x(15))+x(3)-(1-x(5))*(1-x(15))-(1-x(5))*x(3)-(1-x(15))*x(3)+(1-x(5))*(1-x(15))*x(3);
F(7) = -1+(1-x(5))+(1-x(16))+x(2)-(1-x(5))*(1-x(16))-(1-x(5))*x(2)-(1-x(16))*x(2)+(1-x(5))*(1-x(16))*x(2);
F(8) = -1+(1-x(5))+(1-x(18))+x(3)-(1-x(5))*(1-x(18))-(1-x(5))*x(3)-(1-x(18))*x(3)+(1-x(5))*(1-x(18))*x(3);
F(9) = -1+(1-x(6))+(1-x(14))+x(3)-(1-x(6))*(1-x(14))-(1-x(6))*x(3)-(1-x(14))*x(3)+(1-x(6))*(1-x(14))*x(3);
F(10) = -1+(1-x(6))+(1-x(15))+(1-x(20))+x(3)-(1-x(6))*(1-x(15))-(1-x(6))*(1-x(20))-(1-x(6))*x(3)-(1-x(15))*(1-x(20))-(1-x(15))*x(3)-(1-x(20))*x(3)+(1-x(6))*(1-x(15))*(1-x(20))+(1-x(6))*(1-x(15))*x(3)+(1-x(6))*(1-x(20))*x(3)+(1-x(15))*(1-x(20))*x(3)-(1-x(6))*(1-x(15))*(1-x(20))*x(3);
F(11) = -1+(1-x(6))+(1-x(15))+(1-x(21))+x(2)-(1-x(6))*(1-x(15))-(1-x(6))*(1-x(21))-(1-x(6))*x(2)-(1-x(15))*(1-x(21))-(1-x(15))*x(2)-(1-x(21))*x(2)+(1-x(6))*(1-x(15))*(1-x(21))+(1-x(6))*(1-x(15))*x(2)+(1-x(6))*(1-x(21))*x(2)+(1-x(15))*(1-x(21))*x(2)-(1-x(6))*(1-x(15))*(1-x(21))*x(2);
F(12) = -1+(1-x(6))+(1-x(16))+x(2)-(1-x(6))*(1-x(16))-(1-x(6))*x(2)-(1-x(16))*x(2)+(1-x(6))*(1-x(16))*x(2);
F(13) = -1+(1-x(6))+(1-x(17))+x(2)-(1-x(6))*(1-x(17))-(1-x(6))*x(2)-(1-x(17))*x(2)+(1-x(6))*(1-x(17))*x(2);
F(14) = -1+(1-x(6))+(1-x(18))+x(2)-(1-x(6))*(1-x(18))-(1-x(6))*x(2)-(1-x(18))*x(2)+(1-x(6))*(1-x(18))*x(2);
F(15) = -1+(1-x(7))+x(3)-(1-x(7))*x(3);
F(16) = -1+(1-x(8))+x(2)-(1-x(8))*x(2);
F(17) = -1+x(4);
F(18) = -1+x(11);
err = norm(F);
