The ornamental design for a watch, substantially as shown and described.
FIG. 1 is a top plan view of a watch showing my new design;
FIG. 2 is a top plan view of the watch shown with a rotatable dial segment in an alternate position and the hour and minute hands showing a different time;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a front elevation thereof;
FIG. 5 is a rear elevation thereof;
FIG. 6 is a right side elevation thereof;
FIG. 7 is a left side elevation thereof;
FIG. 8 is a right front perspective view of the watch shown with a rotatable dial segment in an alternate position; and,
FIG. 9 is a right rear perspective view thereof.
The broken lines in the drawings are used to show a watch band that does not form part of the claimed design.