A salary that’s acceptable to them.
Personally, I don’t need the most money somebody is willing to pay me. I need enough money for my goals in life. In fact, I’ll happily accept a number that’s lower than an employer’s maximum because it makes me a good value.
If their number is less than my number, I ask for my number plus a little bit and they say either yes/no. No stress and I’m perfectly happy either way.