The University President Concocts a Thirteen-Step Sinister Plan to Lower

The university president concocts a thirteen-step sinister plan to lower morale to zero during his last year in office. The duration of each step (in days)and the required predecessor(s)are displayed in the table.
$$\begin{array} { | c | c | c | } \hline \text { Activity } & \text { Duration } & \text { Predecessor } \\\hline \text { A } & 3 & - \cdot \\\hline \text { B } & 8 & \cdots \\\hline \text { C } & 8 & \text { A } \\\hline \text { D } & 7 & \text { B } \\\hline \text { E } & 4 & \text { B } \\\hline \text { F } & 4 & \text { C,D } \\\hline \text { G } & 8 & \text { C,D } \\\hline \text { H } & 8 & \text { E } \\\hline \text { I } & 4 & \text { F } \\\hline \text { J } & 2 & \text { G } \\\hline \text { K } & 6 & \text { H } \\\hline \text { L } & 10 & \text { I } \\\hline \text { M } & 7 & \mathrm {~J} , \mathrm {~K} \\\hline\end{array}$$ What are the early and late start and finish times for this morale-lowering project?