Backpack

FIG. 1 is a top, front, right perspective view of a backpack showing our new design;

FIG. 2 is a right side view thereof;

FIG. 3 is a left side view thereof; and,

FIG. 4 is a top, rear, perspective view of a backpack in an alternative configuration thereof.

The broken lines represent portions of the backpack or stitching and form no part of the claimed design.