The ornamental design for a lamp, as shown and described.
The file of this patent contains at least one drawing executed in color. Copies of this patent with color drawings will be provided by the Patent and Trademark 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.