Some math:
There are 88 entries in this list.
88 * 64 bits = 5,632 bits.
5,632 bits / 8 bits per byte = 704 Bytes.

Found what happened, nevermind.

So, I can't pass the fixed tests (and only the fixed tests, I passed on everything else) in the full suite. The only error I get is this:
Expected: equal to ""
Actual: "

Even after implementing this line right before returning:
res.erase(std::remove(res.begin(), res.end(), ' '), res.end());
which removes all spaces, I get the same error.

This is for C++, and I have no idea how I would end up with a singular double-quotation mark, as strings are represented with 2 double-quotation marks.

Vague error message, could not complete Kata.