Score : $500$ points

## 问题陈述

已知长度为 $N$ 的序列 $A$。你可以执行任意次数的操作：当序列长度至少为 $2$ 时，选择两个相邻的数值，删除它们，并将它们的和插入到原来的位置。经过零次或多次操作后，可以得到多少种不同的序列？请在求得结果后对 $998244353$ 取模。

以上为通义千问 qwen-max 翻译，仅供参考。

Problem Statement

Given is a sequence $A$ of length $N$. You can do this operation any number of times: when the length of the sequence is at least $2$, choose two adjacent values, delete them, and insert their sum where they were. How many sequences can result from zero or more operations? Find the count modulo $998244353$.

Constraints

• $1 \leq N \leq 2\times 10^5$
• $|A_i| \leq 10^9$
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

$N$

$A_1$ $A_2$ $\cdots$ $A_N$

Output

Print the answer.

Sample Input 1

3
1 -1 1

Sample Output 1

4

The following four sequences can result from zero or more operations.

• ${1,-1,1}$
• ${1,0}$
• ${0,1}$
• ${1}$

Sample Input 2

10
377914575 -275478149 0 -444175904 719654053 -254224494 -123690081 377914575 -254224494 -21253655

Sample Output 2

321

update @ 2024/3/10 10:03:49