Backpack

FIG. 1 is a rear view of a backpack;

FIG. 2 is a front view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a left view thereof; and,

FIG. 7 is a perspective view thereof showing rear and left views.

The broken lines depict portions of the backpack that form no part of the claimed design.