The ornamental design for shirt, as shown and described.
FIG. 1 is a perspective view of a shirt according to the claimed design;
FIG. 2 is a front elevational view of the shirt of FIG. 1;
FIG. 3 is a rear elevational view of the shirt of FIG. 1;
FIG. 4 is a right side elevational view of the shirt of FIG. 1;
FIG. 5 is a left side elevational view of the shirt of FIG. 1; and,
FIG. 6 is a top elevational view of the shirt of FIG. 1.
The features shown in heavy broken lines (i.e., the shirt pockets, triangular hem reinforcement, and buttons) represent portions of the shirt which form no part of the claimed design. The remaining shorter, lighter broken lines represent stitching. Interior regions of the shirt are not part of the claimed design.