There is a crazy circuit board with three kinds of elements which can change the signal value. All intersecting paths are connected (but paths touching by a single point are disconnected).
There is an input line (marked blue) and an output line (marked red).
The circuit can operate with decimal numbers for your convenience. The input value is shown in the left corner. The actions peformed on the signal $s$ by each kind of elements are shown in the right corner.
Choose the path from the input to the output, which gives the largest positive number in the end. Show the path and the resulting value.
Believe it or not, this crazy board is created by a simple cellular automaton with the following rule:
(this has nothing to do with the problem, but this way you can create your own picture if you want).