The ornamental design for a hat, as shown and described.
FIG. 1 is a front perspective view with an opening at the apex of the design;
FIG. 2 is a front view of the design;
FIG. 3 is a left side view of the design;
FIG. 4 is a right side view of the design;
FIG. 5 is a back side view of the design;
FIG. 6 is a top side view with an opening at the center of the design;
FIG. 7 is a bottom side view with an opening at the center of the design; and,
FIG. 8 is a rear perspective view.
The broken lines illustrating the elements of a pattern along the brim depict features of the hat that form no part of the claimed design. The broken line depiction of the partial human figure in FIG. 8 shows the hat in a position of used and forms no part of the claimed design.