The ornamental design for a comb, as shown and described.
FIG. 1 is a front view of a comb showing my new design.
FIG. 2 is a left side view of the comb of FIG. 1.
FIG. 3 is a right side view of the comb of FIG. 1.
FIG. 4 is a top view of the comb of FIG. 1.
FIG. 5 is a bottom view of the comb of FIG. 1
FIG. 6 is a top section view of the comb of FIG. 1, taken in the direction of line 6-6 in FIG. 1; and,
FIG. 7 is a front perspective view of the comb of FIG. 1.
The broken lines in the drawings depict portions of the comb that form no part of the claimed design. The dash-dot broken line shown in the drawings depicts the boundary of the claim and forms no part of the claimed design.