The ornamental design for a football, as shown and described.
FIG. 1 is a top plan view showing our new design for a football;
FIG. 2 is a bottom plan view of the football of FIG. 1;
FIG. 3 is a right-side elevational view of the football of FIG. 1;
FIG. 4 is a left-side elevational view of the football of FIG. 1;
FIG. 5 is a front elevational view of the football of FIG. 1;
FIG. 6 is a rear elevation view of the football of FIG. 1; and,
FIG. 7 is perspective view of a top, right-side, and left-side of the football of FIG. 1.
The broken line surrounding the lace portions represent stitching. All broken lines, including the stitching, depict portions of the football that form no part of the claimed design.