FIG. 1 is a front elevational view of a first embodiment of the ornamental design for a lamp;
FIG. 2 is a left side elevational view of the first embodiment;
FIG. 3 is a rear elevational view of the first embodiment;
FIG. 4 is a top plan view of the first embodiment;
FIG. 5 is a bottom plan view of the first embodiment; and
FIG. 6 is a perspective view of the first embodiment, as seen from the front, top side.
FIG. 7 is a front elevational view of a second embodiment of the ornamental design for a lamp, the design being rotationally symmetric;
FIG. 8 is a top plan view of the second embodiment;
FIG. 9 is a bottom plan view of the second embodiment; and,
FIG. 10 is a perspective view of the second embodiment, as seen from the front, top side.
The broken line disclosure is for environmental purposes only and does not form a part of the claimed design.