The ornamental design for a hat, as shown and described.
FIG. 1 is a perspective view of my new hat design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines illustrate portions of the hat that form no part of the claimed design. The unshaded areas adjacent to the shaded areas of the hat form no part of the claimed design.