The ornamental design for a sandal with removabletop, as shown and described.
FIG. 1 is a side perspective view of a sandal with removable top showing my new design;
FIG. 2 is a front perspective view thereof.
FIG. 3 is a left side view thereof.
FIG. 4 is a right side view thereof; and,
FIG. 5 is a top view thereof.
The unshaded regions form no part of the claimed design. The broken lines showing the remainder of the sandal with removable top are for environmental purposes only and form no part of the claimed design.