First Occurrence Maximum Subarray Index

You are given an array of integers. Your task is to find the starting index of the first occurrence of a contiguous subarray that has the maximum sum among all possible contiguous subarrays. If the array is empty, output -1.

The contiguous subarray is defined as a sequence of consecutive elements from the original array. Formally, if the array is denoted as \(a_0, a_1, \dots, a_{n-1}\), you need to find an index \(i\) and a length \(l\) (with \(1 \leq l \leq n\)) such that the sum \(S = \sum_{j=i}^{i+l-1} a_j\) is maximized. If there are multiple such subarrays, choose the one with the smallest starting index \(i\).

Note: In case the input array is empty, the result should be \(-1\).

inputFormat

The input is given via standard input (stdin) and consists of two lines:

1. The first line contains an integer \(n\) (which can be 0), representing the number of elements in the array.
2. If \(n > 0\), the second line contains \(n\) space-separated integers denoting the elements of the array.

outputFormat

Output a single integer through standard output (stdout), which is the starting index of the contiguous subarray that has the maximum sum. If the array is empty, output \(-1\).

## sample

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