The discrete-time Fourier transform of a signal \(x[n]\) is
\[
X(\Omega) = (1 + \cos \Omega) e^{-j\Omega}
\]
Consider that \(x_p[n]\) is a periodic signal of period \(N = 5\) such that
\[
x_p[n] = x[n], \; n = 0,1,2, x_p[n] = 0, \; n=3,4
\]
Note that \(x_p[n] = \sum_{k=0}^{N-1} a_k e^{j\frac{2\pi}{N}kn}\). The magnitude of the Fourier series coefficient \(a_3\) is ................ (Round off to 3 decimal places).