Longest Path in a acyclic, directed graph [duplicate]

Is there a known algorithm which finds the longest path in an acyclic, directed graph like the one below?

For this example, the algorithm should calculcate a longest path of 28m

marked as duplicate by user91500, hardmath, Daniel W. Farlow, user137731, David KNov 27 '16 at 15:33

I hope this helps $\ddot\smile$