CF962A.Equator

Polycarp has created his own training plan to prepare for the programming contests. He will train for $n$ days, all days are numbered from $1$ to $n$, beginning from the first.

On the $i$-th day Polycarp will necessarily solve $a_i$ problems. One evening Polycarp plans to celebrate the equator. He will celebrate it on the first evening of such a day that from the beginning of the training and to this day inclusive he will solve half or more of all the problems.

Determine the index of day when Polycarp will celebrate the equator.

Polycarp 为自己制定了编程竞赛训练计划。他将进行 $n$ 天的训练，所有天数从 $1$ 到 $n$ 编号，从第一天开始。

在第 $i$ 天，Polycarp 必定会解决 $a_i$ 道题目。某天晚上，Polycarp 计划庆祝“赤道日”（equator）。他将在满足如下条件的最早一天的晚上庆祝：从训练开始到该天（含）为止，他所解决的题目总数达到全部题目总数的一半或更多。

请确定 Polycarp 庆祝赤道日的那天的编号（即天数索引）。

The first line contains a single integer $n$ ($1 \le n \le 200\,000$) — the number of days to prepare for the programming contests.

The second line contains a sequence $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10\,000$), where $a_i$ equals to the number of problems, which Polycarp will solve on the $i$-th day.

第一行包含一个整数 $n$（$1 \le n \le 200\,000$）—— 表示为编程竞赛做准备的天数。

第二行包含一个序列 $a_1, a_2, \dots, a_n$（$1 \le a_i \le 10\,000$），其中 $a_i$ 表示 Polycarp 在第 $i$ 天将要解决的问题数量。

Print the index of the day when Polycarp will celebrate the equator.

输出 Polycarp 庆祝“赤道日”的那一天的索引。

In the first example Polycarp will celebrate the equator on the evening of the second day, because up to this day (inclusive) he will solve $4$ out of $7$ scheduled problems on four days of the training.

In the second example Polycarp will celebrate the equator on the evening of the third day, because up to this day (inclusive) he will solve $6$ out of $12$ scheduled problems on six days of the training.

在第一个例子中，Polycarp 将在第二天晚上庆祝“赤道日”，因为截至这一天（含当天），他在训练的四天内共解出了计划的 $7$ 道题中的 $4$ 道。

在第二个例子中，Polycarp 将在第三天晚上庆祝“赤道日”，因为截至这一天（含当天），他在训练的六天内共解出了计划的 $12$ 道题中的 $6$ 道。