A thought of 1b/c encoding way

[837951602]

Write the binary series of even chars into a string of [ and ]
 [[][[[][[]
choose a part(can be always from somewhere to the end) and reverse so that cnt([) = cnt(])
[[][ ]][]][
choose a point spliting the string into 2 part and swap
          [[[][]][]]
turn the 3rd+ [] into (), so that if Array/Function.prototype[any] is function it's called
          [[[][]][]]
turn [x][] into +[x] and [x][][] to [x]+[], [x][][][] into [x]+[[]], etc
          [ +[ +[]]]