```
The nesting depth of a balanced string of parentheses is the maximum, over all prefixes of the string, of the excess number of ('s within the prefix. For example, the string ()()() has nesting depth 1, but the string ((()))() has nesting depth 3, as we can see clearly if we count excess ('s for every prefix of the string:
```
by Leap_Frog @ 2021-04-25 10:03:20
@[mrsrz](/user/6813)
by Leap_Frog @ 2021-04-25 10:03:39
fixed
by mrsrz @ 2021-04-25 11:07:19