We claim the ornamental design for a bench, as shown and described.
FIG. 1 is front view of a bench;
FIG. 2 is rear view of the bench;
FIG. 3 is a left side view of the bench;
FIG. 4 is a right side view of the bench;
FIG. 5 is a top view of the bench;
FIG. 6 is a bottom view of the bench; and,
FIG. 7 is a perspective view of the bench.
Any subject matter shown in dashed lines, and any surfaces of the design not shown, including interior surfaces, form no part of the claimed invention.