The ornamental design for jeans, as shown and described.
FIG. 1 is a front perspective view of jeans showing our new design;
FIG. 2 is a front elevational view of the jeans of the present invention;
FIG. 3 is a rear elevational view of the jeans of the present invention;
FIG. 4 is a left side elevational view of the jeans of the present invention, the undisclosed right side elevational view being a mirror image thereof;
FIG. 5 is a top plan view of the jeans of the present invention; and,
FIG. 6 is a bottom plan view of the jeans of the present invention.