Problem Statement
You are given a connected simple undirected graph consisting of $N$ vertices and $M$ edges.
For $i = 1, 2, \ldots, M$, the $i$-th edge connects vertex $u_i$ and vertex $v_i$.
Takahashi starts at Level $0$ on vertex $1$, and will perform the following action exactly $K$ times.
- First, choose one of the vertices adjacent to the vertex he is currently on, uniformly at random, and move to the chosen vertex.
- Then, the following happens according to the vertex
$v$he has moved to. - If
$C_v = 0$: Takahashi's Level increases by$1$.- If
$C_v = 1$: Takahashi receives a money of$X^2$yen, where$X$is his current Level.
- If
Print the expected value of the total amount of money Takahashi receives during the $K$ actions above, modulo $998244353$ (see Notes).
Note
It can be proved that the sought expected value is always a rational number. Additionally, under the Constraints of this problem, when that value is represented as $\frac{P}{Q}$ using two coprime integers $P$ and $Q$, it can also be proved that there is a unique integer $R$ such that $R \times Q \equiv P\pmod{998244353}$ and $0 \leq R \lt 998244353$. Find this $R$.
Constraints
$2 \leq N \leq 3000$$N-1 \leq M \leq \min\lbrace N(N-1)/2, 3000\rbrace$$1 \leq K \leq 3000$$1 \leq u_i, v_i \leq N$$u_i \neq v_i$$i \neq j \implies \lbrace u_i, v_i\rbrace \neq \lbrace u_j, v_j \rbrace$- The given graph is connected.
$C_i \in \lbrace 0, 1\rbrace$- All values in the input are integers.
Input
The input is given from Standard Input in the following format:
N M K
u_1 v_1
u_2 v_2
\vdots
u_M v_M
C_1 C_2 \ldots C_N
Output
Print the answer.
样例
5 4 8
4 5
2 3
2 4
1 2
0 0 1 1 0
89349064
8 12 20
7 6
2 6
6 4
2 1
8 5
7 2
7 5
3 7
3 5
1 8
6 3
1 4
0 0 1 1 0 0 0 0
139119094
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