The ornamental design for a bag, as shown and described.
FIG. 1 is a perspective view of the bag embodying the new design, including a carrying cord shown in broken lines;
FIG. 2 is a perspective view of the bag embodying the new design;
FIG. 3 is a top plan view thereof;
FIG. 4 is a right side view, the left side being a mirror image thereof;
FIG. 5 is a front view thereof; and,
FIG. 6 is a rear view thereof.
FIG. 1 shows a carrying cord feature for the bag in broken lines. This feature is shown for environmental purposes and does not form any part of the claimed design. FIGS. 1–3 show a second set of broken/dotted lines on the surface of the claimed design. The dotted lines on the surface of the claimed design represent stitching.