The ornamental design for a bench, as shown and described.
FIG. 1 is a perspective view of a bench showing my new design.
FIG. 2 is a front view thereof.
FIG. 3 is a rear view thereof.
FIG. 4 is a side view thereof.
FIG. 5 is an opposite side view thereof.
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The evenly space broken lines in the drawings depict portions of the bench that form no part of the claimed design. The bench is shown with dash-dot symbolic break lines indicating that the appearance of any portion of the bench between the break lines forms no part of the claimed design.