The ornamental design for a lamp, as shown and described.
1. Lamp
1.1 : Perspective
1.2 : Perspective
1.3 : Perspective
1.4 : Bottom
1.5 : Front
1.6 : Top
1.7 : Left
1.8 : Right
In Figure 1.3 the lamp is shown with the band dismounted; the broken lines in the drawings illustrate break lines which form no part of the claimed design; the break lines indicate that the appearance of any portion of the lamp between the break lines forms no part of the claimed design.
In Figures 1.2 and 1.4, in addition to the broken lines illustrating break lines, broken lines are shown that illustrate portions of the lamp that form no part of the claimed design.