Problem Statement
For a positive rational number $x$, define $f(x)$ as follows:
Express
$x$as$\dfrac{P}{Q}$using coprime positive integers$P$and$Q$.$f(x)$is defined as the value$P\times Q$.
You are given a positive integer $N$ and a sequence $A=(A_1,A_2,\dots,A_{N-1})$ of positive integers of length $N-1$.
We call a sequence $S=(S_1,S_2,\dots,S_N)$ of positive integers of length $N$ a good sequence if it satisfies all of the following conditions:
- For every integer
$i$with$1\leq i\leq N-1$, it holds that$f\left(\dfrac{S_i}{S_{i+1}}\right)=A_i$. $\gcd(S_1,S_2,\dots,S_N)=1$.
Define the score of a sequence as the product of all its elements.
It can be proved that there are finitely many good sequences. Find the sum, modulo $998244353$, of the scores of all good sequences.
Constraints
$2\leq N\leq 1000$$1\leq A_i\leq 1000$$(1\leq i\leq N-1)$- All input values are integers.
Input
The input is given from Standard Input in the following format:
N
A_1 A_2 \dots A_{N-1}
Output
Print the sum, modulo $998244353$, of the scores of all good sequences.
样例
6
1 9 2 2 9
939634344
2
9
18
25
222 299 229 22 999 922 99 992 22 292 222 229 992 922 22 992 222 222 99 29 92 999 2 29
192457116
题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。