If z=cos(2π/5)+isin(2π/5)z = \cos(2\pi/5) + i\sin(2\pi/5)z=cos(2π/5)+isin(2π/5), calculate 1+z+z2+z3+z41 + z + z^2 + z^3 + z^41+z+z2+z3+z4.
111
000
555
z5z^5z5