[2,3,4],1 gives 22 not 20?
2nd brewed +2, 3&4 waiting +2+2, cleaning +2, Brewing for 3 +3, 4 waiting +3, cleaning +2, brewing for 4 +4.
20, Where do i miss the last +2?
There is no cleaning afterwards. [0,0,1] gives 1.
/edit I forgot cleaning takes time of everyone left in line! So not +2 but +4 Ugh

Strings are fun! 0 is a number, empty array is still array, invisible string is still a string!
Comparing to custom roman numerals decoding or getting rule30 1st time, this was a breeze. Thx

Adding 2 examples to hint numbers "CD" & "XL" & "XC" are also required, would save somebody a bit of time.