Translate the following into a PDE with boundary conditions

The left end of a rod of length L is held at temperature $20$, and there is heat transfer from the right end into the surrounding medium, which has constant temperature zero. The initial temperature $x$ units from the left end of the rod is $\displaystyle 20e^{xL-x^{2}}$. How to enter the answers.

The PDE is
The boundary values / initial conditions are:
Left end is held at temperature $20$:
Heat transfer from the right end into the surrounding medium at temperature zero:
Initial temperature is $\displaystyle 20e^{xL-x^{2}}$: