> p:=sqrt(2)/2:

> with(plottools):with(plots):

> s1:=sphere([1,1,0],p):

> s2:=sphere([1,-1,0],p):

> s3:=sphere([-1,-1,0],p):

> s4:=sphere([-1,1,0],p):

> t1:=sphere([0,1,1],p):

> t2:=sphere([0,1,-1],p):

> t3:=sphere([0,-1,-1],p):

> t4:=sphere([0,-1,1],p):

> u1:=sphere([1,0,1],p):

> u2:=sphere([-1,0,1],p):

> u3:=sphere([-1,0,-1],p):

> u4:=sphere([1,0,-1],p):

> display(s1,s2,s3,s4,t1,t2,t3,t4,u1,u2,u3,u4,scaling=constrained);