Set of building blocks

FIG. 1 is a rear, right and bottom perspective view of a set of building blocks, showing our new design;

FIG. 2 is a front, left and top perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is an enlarged left side view thereof;

FIG. 6 is an enlarged right side view thereof;

FIG. 7 is a an enlarged top plan view thereof; and,

FIG. 8 is an enlarged bottom plan view thereof.

The broken lines shown in the drawings illustrate portions of the set of building blocks that form no part of the claimed design.