The ornamental design for a hat, as shown and described.
FIG. 1 is a rear perspective view of the design, showing an opening at the top being closed by two buttons;
FIG. 2 is a rear side view of the design;
FIG. 3 is a front right side view of the design;
FIG. 4 is a front left side view of the design;
FIG. 5 is a left side view of the design, the right side being the same thereto;
FIG. 6 is a top side view of the design;
FIG. 7 is a bottom side view of the design; and,
FIG. 8 is a rear perspective view of the design, showing the opening at the top being opened.
The broken line depiction of the partial human figure in FIG. 8 assists in illustrating how the claimed design may appear when worn. The broken lines form no part of the claimed design.