Numerical Methods: Euler to Runge–Kutta · Hard problem

The trapezoidal method $y_{n+1} = y_n + \dfrac{h}{2}\left(f(t_n, y_n) + f(t_{n+1}, y_{n+1})\right)$ is applied to $y' = -y$, $y(0) = 1$, with $h = \dfrac{1}{2}$. Find the estimate of $y(1)$ after two steps. Express your answer as a common fraction.