Description: Cirno has a DAG (Directed Acyclic Graph) with $$$n$$$ nodes and $$$m$$$ edges. The graph has exactly one node that has no out edges. The $$$i$$$-th node has an integer $$$a_i$$$ on it. Every second the following happens: - Let $$$S$$$ be the set of nodes $$$x$$$ that have $$$a_x > 0$$$. - For all $$$x \in S$$$, $$$1$$$ is subtracted from $$$a_x$$$, and then for each node $$$y$$$, such that there is an edge from $$$x$$$ to $$$y$$$, $$$1$$$ is added to $$$a_y$$$. Find the first moment of time when all $$$a_i$$$ become $$$0$$$. Since the answer can be very large, output it modulo $$$998\,244\,353$$$. Input Format: The first line contains a single integer $$$t$$$ ($$$1 \leq t \leq 1000$$$) — the number of test cases. Description of test cases follows. The first line of each test case contains two integers $$$n, m$$$ ($$$1 \leq n, m \leq 1000$$$) — the number of vertices and edges in the graph. The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$0 \leq a_i \leq 10^9$$$) — the integer on vertices. Each line of the following $$$m$$$ lines contains two integers $$$x, y$$$ ($$$1 \leq x, y \leq n$$$), represent a directed edge from $$$x$$$ to $$$y$$$. It is guaranteed that the graph is a DAG with no multi-edges, and there is exactly one node that has no out edges. It is guaranteed that both sum of $$$n$$$ and sum of $$$m$$$ over all test cases are less than or equal to $$$10\,000$$$. Output Format: For each test case, print an integer in a separate line — the first moment of time when all $$$a_i$$$ become $$$0$$$, modulo $$$998\,244\,353$$$. Note: In the first test case: - At time $$$0$$$, the values of the nodes are $$$[1, 1, 1]$$$. - At time $$$1$$$, the values of the nodes are $$$[0, 1, 1]$$$. - At time $$$2$$$, the values of the nodes are $$$[0, 0, 1]$$$. - At time $$$3$$$, the values of the nodes are $$$[0, 0, 0]$$$. So the answer is $$$3$$$. - At time $$$0$$$, the values of the nodes are $$$[1, 0, 0, 0, 0]$$$. - At time $$$1$$$, the values of the nodes are $$$[0, 1, 0, 0, 1]$$$. - At time $$$2$$$, the values of the nodes are $$$[0, 0, 1, 0, 0]$$$. - At time $$$3$$$, the values of the nodes are $$$[0, 0, 0, 1, 0]$$$. - At time $$$4$$$, the values of the nodes are $$$[0, 0, 0, 0, 1]$$$. - At time $$$5$$$, the values of the nodes are $$$[0, 0, 0, 0, 0]$$$. In the third test case: The first moment of time when all $$$a_i$$$ become $$$0$$$ is $$$6\cdot 998244353 + 4$$$.