The ornamental design for a bag, as shown and described.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
1. Bag
1.1 : Front
1.2 : Back
1.3 : Top
1.4 : Bottom
1.5 : Right
1.6 : Left
1.7 : Perspective
In the figures, the broken lines illustrate stitching that forms part of the claimed design. The handle/strap disclosed in blue forms NO part of the claimed design.