I claim the ornamental design for a cutting implement, as shown and described.
FIG. 1 is a front/right/top photographic view of the embodiment of the cutting implement;
FIG. 2 is a rear/left/top photographic view thereof;
FIG. 3 is a front photographic view thereof;
FIG. 4 is a rear photographic view thereof;
FIG. 5 is a right side photographic view thereof, wherein the left side photographic view would be a mirror image thereof (mirrored both horizontally and vertically; i.e., rotated 180 degrees with respect to FIG. 5);