An open box layout consists of a continuous vertical strip with four square faces ordered S, T, U, V from top to bottom. Two side flaps W and Z are connected laterally to the edges of this strip. When this template is folded to form a cube, which letter would be on the face opposite U?

In any linear sequence of four squares in an open dice layout, the alternate faces are positioned opposite to each other upon folding. Analyzing the continuous vertical strip containing S, T, U, V:
* S is alternate to U $⟹$ S is opposite U.
* T is alternate to V $⟹$ T is opposite V.

Therefore, the face that lies directly opposite to face U is S.