FIG. 1 is an isometric view of an ornamental design for a puzzle showing my new design;
FIG. 2 is a front orthographic view thereof, the rear, left side, and right side orthographic views being identical thereto;
FIG. 3 is a top orthographic view thereof, the bottom orthographic view being identical thereto; and,
FIG. 4 is an isometric view of a second embodiment of a puzzle showing my design.
The broken lines shown in FIGS. 1-4 are included for the purposes of illustrating environmental elements only and form no part of the claimed design.