Which of the following expressions is not meaningful?

$\vec u.(\vec v×\vec w)$ $(\vec u.\vec v).\vec w$ $(\vec u.\vec v)\vec w$ $\vec u×(\vec v×\vec w)$

$(\vec u.\vec v).\vec w$

Clearly $(\vec u.\vec v).\vec w$ is not meaningful as dot product of scalar & vectors is not defined.