We claim the ornamental design for a knife, as shown and described.
FIG. 1 is a perspective view of a knife according to the invention.
FIG. 2 is a right side view of the knife shown in FIG. 1.
FIG. 3 is a left side view of the knife shown in FIG. 1.
FIG. 4 is a front end view of the knife shown in FIG. 1.
FIG. 5 is a back end view of the knife shown in FIG. 1.
FIG. 6 is a top plan view of the knife shown in FIG. 1; and,
FIG. 7 is a bottom plan view of the knife shown in FIG. 1.
The present application is directed to the design illustrated in the drawings. The elements shown in broken lines are included for the purpose of illustrating environment and form no part of the claimed design.