The ornamental design for a hat, as shown and described.
FIG. 1 is a front perspective view of the hat;
FIG. 2 is a front elevation view of the hat, the rear elevation view being a mirror image thereof;
FIG. 3 is a left side elevation view of the hat, the right side elevation view being a mirror image thereof; and,
FIG. 4 is a plan view of the hat from above, is not shown because it has no ornamental content.
FIGS. 1–4, the broken lines showing the brim of the hat are for the purpose of illustrating environmental structure only and form no part of the claimed design.