CF1067A.Array Without Local Maximums

Ivan unexpectedly saw a present from one of his previous birthdays. It is array of $n$ numbers from $1$ to $200$. Array is old and some numbers are hard to read. Ivan remembers that for all elements at least one of its neighbours ls not less than it, more formally:

$a_{1} \le a_{2}$,

$a_{n} \le a_{n-1}$ and

$a_{i} \le max(a_{i-1}, \,\, a_{i+1})$ for all $i$ from $2$ to $n-1$.

Ivan does not remember the array and asks to find the number of ways to restore it. Restored elements also should be integers from $1$ to $200$. Since the number of ways can be big, print it modulo $998244353$.

伊万意外地发现了一个来自他之前某次生日的礼物。它是一个由 $n$ 个介于 $1$ 到 $200$ 之间的整数组成的数组。这个数组年代久远，其中一些数字已难以辨认。伊万记得：对于数组中每个元素，其至少一个相邻元素不小于它。更准确地说，满足以下条件：

$a_{1} \le a_{2}$，

$a_{n} \le a_{n-1}$，且

对所有 $i$ 从 $2$ 到 $n-1$，均有 $a_{i} \le \max(a_{i-1}, \,\, a_{i+1})$。

伊万已记不清该数组的具体内容，因此请求你计算出恢复该数组的方案数。被恢复的元素也必须是 $1$ 到 $200$ 之间的整数。由于方案数可能很大，请将结果对 $998244353$ 取模后输出。

First line of input contains one integer $n$ ($2 \le n \le 10^{5}$) — size of the array.

Second line of input contains $n$ integers $a_{i}$ — elements of array. Either $a_{i} = -1$ or $1 \le a_{i} \le 200$. $a_{i} = -1$ means that $i$-th element can't be read.

输入的第一行包含一个整数 $n$（$2 \le n \le 10^{5}$）—— 数组的大小。

输入的第二行包含 $n$ 个整数 $a_{i}$ —— 数组的元素。每个 $a_{i}$ 要么为 $-1$，要么满足 $1 \le a_{i} \le 200$。其中 $a_{i} = -1$ 表示第 $i$ 个元素不可读。

Print number of ways to restore the array modulo $998244353$.

输出恢复数组的方法数对 $998244353$ 取模的结果。

In the first example, only possible value of $a_{2}$ is $2$.

In the second example, $a_{1} = a_{2}$ so there are $200$ different values because all restored elements should be integers between $1$ and $200$.

在第一个例子中，$a_{2}$ 的唯一可能取值是 $2$。

在第二个例子中，$a_{1} = a_{2}$，因此共有 $200$ 个不同的取值，因为所有恢复出的元素都必须是介于 $1$ 和 $200$ 之间的整数。