Start Shift

*This is the easy version of the problem. You only need to check whether the given array is balanced.* You are given an array $A$ of length $2N$. The array contains every integer from $1$ to $N$ **exactly twice each**. You can modify the array via the following process: - Choose an integer $k$ ($0 \le k \le 2N$). - Choose $k$ indices in ascending order: $1 \le i_1 \lt i_2 \lt \ldots \lt i_k \le