The ornamental design for a shovel, as shown, and described.
FIG. 1 is a front perspective view of the shovel of the present invention;
FIG. 2 is a front view of the shovel of FIG. 1;
FIG. 3 is a left side view of the shovel of FIG. 1 as seen from a left side of FIG. 2, the right side being a mirror image thereof; and,
FIG. 4 is a left side view of the shovel of FIG. 1 having the second shaft unattached to the main shaft, as seen from a left side of FIG. 2, the right side being a mirror image thereof.
The broken lines represent portions of the article and form no part of the claimed design.