The ornamental design for a watch, as shown and described.
FIG. 1 is a right front perspective view of a watch showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a right side elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The structural features depicted by broken lines in FIG. 5 have been shown for the purpose of illustrating portions of the watch that form no part of the claimed design.
The rear of the watch, not shown, forms no part of the claimed design.