The ornamental design for a guidewire, as shown and described.
FIG. 1 is a perspective view of the guide wire;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right-side elevational view thereof; and,
FIG. 7 is a left-side elevational view thereof.
The evenly spaced broken lines in the drawings are for the purpose of illustrating portions of the guide wire that form no part of the claimed design. The dot-dash broken lines depict a boundary of the claimed subject matter and form no part of the claimed design. The broken line break lines in the drawings indicate that the appearance of any portion of the article between the broken break lines forms no part of the claimed design.