The ornamental design for a screw, as shown and described.
FIG. 1 is a perspective view of the screw showing my new design, taken from the front, top, and right side thereof;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a cross-sectional view thereof taken along the lines 8-8 in FIG. 6, illustrating the configuration of the groove formed in the screw head; and,
FIG. 9 is a cross-sectional view thereof taken along the lines 9-9 in FIG. 6, illustrating the configuration of the groove formed in the screw head.
The broken lines in all figures illustrate portions of the screw that form no part of the claimed design.