The ornamental design for a watch, as shown and described.
FIG. 1 is a perspective view of the present invention;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The structural features depicted by broken lines in the drawings have been shown for the purpose of illustrating portions of the claimed watch that form no part of the claimed design.