There are $n$ projects, indexed from $0$ to $n - 1$. You are given an integer array milestones, where each milestones[i] represents the number of milestones required to complete project $i$.

You plan to work on the projects week by week following these rules:

• In each week, you can complete exactly $1$ milestone of any project.

• You cannot work on milestones of the same project in two consecutive weeks.

Return the maximum number of weeks you can work without violating the given rules.

Constraints:

• n $==$ milestones.length

• $1 \leq$ n $\leq 10^5$

• $1 \leq$ milestones[i] $\leq 10^9$

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.