I claim the ornamental design for a safe, as shown and described.
FIG. 1 is a perspective view of a safe made in accordance with an embodiment of the new design;
FIG. 2 is a front elevation view of the safe of FIG. 1;
FIG. 3 is a left side of the safe of FIG. 1;
FIG. 4 is a rear view of the safe of FIG. 1;
FIG. 5 is a right side view of the safe of FIG. 1;
FIG. 6 is a top view of the safe of FIG. 1; and,
FIG. 7 is a bottom view of the safe of FIG. 1.
The portions of the Figures shown in phantom lines form no part of the claimed design, but are directed to environment and for illustrative purposes only, or are to define the boundaries of the claimed design.