The ornamental design for a seat, substantially as shown and described.
FIG. 1 is a front perspective view of a seat embodying my new design, shown
in the form of a chair;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front perspective view of a seat embodying my new design, shown
in the form of a sofa;
FIG. 4 is a rear perspective view thereof; and
FIG. 5 is a front perspective view of a seat showing my design in the form
of a sectional sofa. The end and rear surfaces not shown in FIG. 5 are
substantially the same in appearance as the end and rear surfaces
disclosed in FIG. 4.