The ornamental design for a lamp, as shown and described.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
1. Lamp
1.1 : Perspective
1.2 : Enlarged
1.3 : Front
1.4 : Bottom
1.5 : Top
The area circled by broken line in FIG. 1.5, as well as the broken line itself, illustrate a portion of the lamp that forms no part of the claimed design.