I am trying to start using FEniCS, but have a problem with the simple hello world examples given in the books. Could you please give me the simplest hello world example for solving the Fick's second law.

$$\frac{\partial c}{\partial t} = D \frac{\partial^2 c}{\partial x^2}$$

How can we apply the boundary condition to the simplest example of FEniCS for solving this PDE (e.g., drawing the concentration profiles at given times)?