题目描述
You are given an integer array $A$ of length $N$, consisting of $0$'s and $1$'s. Let $a$ be initially the array $A$. You are going to perform the following operation $N-1$ times.
- Let $n$ be the current length of $a$. Choose an integer $i$ ($1 \leq i \leq n-1$) and delete the $i$\-th and the $(i+1)$\-th elements of $a$. Then, by letting $x$ and $y$ be the deleted elements, insert either $x\mathbin{\&}y$ or $x\mathbin{|}y$ to the position of the deleted elements. Here $x\mathbin{\&}y$ and $x\mathbin{|}y$ denote the bit-AND and bit-OR operations, respectively.
There are $2^{N-1} \times (N-1)!$ ways to perform the operations. Count the number of ways that result in a single value of $1$, modulo $998244353$.
输入格式
The first line contains an integer $N$ ($1 \leq N \leq 10^6$).
The second line contains integers $A_1,A_2,\ldots,A_N$ ($0 \leq A_i \leq 1$).