If \({\left( {\frac{{\cos \theta + i\sin \theta }}{{\sin \theta + i\cos \theta }}} \right)^{2020}} + {\left( {\frac{{1 + \cos \theta + i\sin \theta }}{{1 - \cos \theta + i\sin \theta }}} \right)^{2021}} = x + iy\), then the value of x + y at \(\theta=\frac{\pi}{2}\) is