The ornamental design for an article of footwear, as shown and described.
FIG. 1 is a lateral side view of an article of footwear;
FIG. 2 is a medial side view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a top perspective view from the lateral side thereof.
The “N” logo shown on the lateral side view, the medial side view, the top plan view, and the top perspective view forms no part thereof. The “NB” logos on the tongue of the article of footwear and on the insole of the article of footwear shown on the top plan view form no part thereof. The “NB” logo on the bottom plan view forms no part thereof.
The broken lines depict portions of the article of footwear that form no part of the claimed design.