Careful! Every row is a positive integer

$\begin{array}{ccccc} & & & & \boxed{\phantom0} &\boxed{\phantom0} \\ \times & & & & \boxed{\phantom0} &\boxed{\phantom0} \\ \hline & & & \boxed{\phantom0} & \boxed{\phantom0} &\boxed{\phantom0} \\ & & \boxed{\phantom0} & \boxed{\phantom0} & \boxed{\phantom0} & \\ \hline & & \boxed{\phantom0}& \boxed{\phantom0} & \boxed{0} &\boxed{0} \\ \end{array}$

The above is an incomplete long multiplication with only the two $0$'s at the bottom filled in. What is the maximum possible value of the result of the multiplication?

Clarification: In the whole process, no number can have a leading digit of 0.