I claim the ornamental design for a hat, as shown and described.
FIG. 1 is a rear perspective view of a hat showing the new design;
FIG. 2 is a rear end view thereof;
FIG. 3 is a front end view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a left side view thereof; and,
FIG. 8 is a rear perspective view thereof showing the hat being worn.
The broken lines illustrating a head and hair shown in FIG. 8 are provided to illustrate the hat being worn and do not form a part of the claimed design.