So, when I have string s ="/"abc" the correct answer would be 4 ("abc) or 5(/"abc) then?

I have such error after testing: https://freeimage.host/i/hzEJl1https://freeimage.host/i/hzEARs
and if link expired, here you have transcript:

'''

Testing for:

s = "+8j4R_gG41a0,jC9!yL7*v'\<8x}oyJxzE3560pH5FR=jSgpgs~2f=:?$%4sb_Z[a4DJCzW+~1ET3}0<#gb]LxK{*BYjVxPM)]]4H

expected 30 to equal 27

'''

so does it mean that the string itself has a double quote mark (") in it at the beginning?

in other examples theres opening and closing quotation mark, but now always (as above), so it's confusing...

in the string 'hchzvfrkmlnozjk' author suggest that answer should be 'chzvfrkmlno' (11 chars) but it can be also 'vfrkmlnozjk' (also 11 chars). I think that theres no other possibility to get longer substring...
so @R-N-Wata, theres no way to include 'j' and have more than 11chars

The description mention that division shoud round numbers down so there should be Math.floor(a/b) instead parseInt() in my opinion.