Brush

FIG. 1 is a first perspective view of a brush showing my new design; FIG. 2 is a front view thereof; FIG. 3 is a back view thereof; FIG. 4 is a left-side view thereof; FIG. 5 is a right-side view thereof; FIG. 6 is a top view thereof; FIG. 7 is a bottom view thereof; and, FIG. 8 is a second perspective view thereof. The broken lines in the drawings represent portions of the brush that form no part of the claimed design.