write a go solution for Description:
Levian works as an accountant in a large company. Levian knows how much the company has earned in each of the n consecutive months — in the i-th month the company had income equal to a_i (positive income means profit, negative income means loss, zero income means no change). Because of the general self-isolation, the first ceil(tfracn2) months income might have been completely unstable, but then everything stabilized and for the last lfloortfracn2rfloor months the income was the same.

Levian decided to tell the directors n-k+1 numbers — the total income of the company for each k consecutive months. In other words, for each i between 1 and n-k+1 he will say the value a_i+a_i+1+ldots+a_i+k-1. For example, if a=[-1,0,1,2,2] and k=3 he will say the numbers 0,3,5.

Unfortunately, if at least one total income reported by Levian is not a profit (income <=0), the directors will get angry and fire the failed accountant.

Save Levian's career: find any such k, that for each k months in a row the company had made a profit, or report that it is impossible.

Input Format:
The first line contains a single integer n (2<=n<=5*10^5) — the number of months for which Levian must account.

The second line contains ceil(n/2) integers a_1,a_2,ldots,a_ceil(n/2), where a_i (-10^9<=a_i<=10^9) — the income of the company in the i-th month.

Third line contains a single integer x (-10^9<=x<=10^9) — income in every month from ceil(n/2)+1 to n.

Output Format:
In a single line, print the appropriate integer k or -1, if it does not exist.

If there are multiple possible answers, you can print any.

Note:
In the first example, k=2 and k=3 satisfy: in the first case, Levian will report the numbers 1,1, and in the second case — one number 3.

In the second example, there is no such k.

In the third example, the only answer is k=4: he will report the numbers 1,2,3.. Output only the code with no comments, explanation, or additional text.