The ornamental design for a cooktop, as shown and described.
The file of this patent contains drawings/photographs of FIGS. 1-3, executed in color. Copies of this patent with color drawings/photographs will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 is a top elevational view of a cooktop according to a first embodiment;
FIG. 2 is a top elevational view of a cooktop according to a second embodiment; and,
FIG. 3 is a top elevational view of a cooktop according to a third embodiment.