The ornamental design for a lamp, substantially as shown and described.
FIG. 1 is a perspective view of a lamp embodying the design of the present
invention.
FIG. 2 is a front side elevational view of the lamp illustrated in FIG. 1,
with the left side elevational view, the right side elevational view and
the back side elevational view being identical thereto.
FIG. 3 is a top view of the lamp of FIG. 1; and,
FIG. 4 is a bottom view of the lamp of FIG. 1.
The lamp shade shown in broken lines does not form a part of the claimed
design.