The ornamental design for a desk, as shown and described.
FIG. 1 is a perspective view of a desk showing the design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a sectional view taken along the section line 3—3 of FIG. 2;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a left elevation view thereof;
FIG. 8 is a right elevation view thereof; and,
FIG. 9 is a perspective view showing an alternative arrangement of the desk, in which the side table is in an alternate position to that shown in FIGS. 1 to 8.
The broken lines are for environmental purposes only and form no part of the claimed design.