nums = [1, 7, 3, 6, 5, 6]
The sum of the numbers to the left of index 3 (nums = 6) is equal to the sum of numbers to the right of index 3.
Also, 3 is the first index where this occurs.
There is no index that satisfies the conditions in the problem statement.
The length of nums will be in the range [0, 10000].
Each element nums[i] will be an integer in the range [-1000, 1000].