题目描述
Problem Statement
You are given a simple undirected graph with N vertices numbered 1 to N and M edges numbered 1 to M. Edge i connects vertex u_i and vertex v_i.
Find the number, modulo 998244353, of ways to write an integer between 1 and K, inclusive, on each vertex of this graph to satisfy the following condition:
- two vertices connected by an edge always have different numbers written on them.
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
Output
Print the number, modulo 998244353, of ways to write integers between 1 and K, inclusive, on the vertices to satisfy the condition.
Constraints
- $1 \leq N \leq 30$
- $0 \leq M \leq \min \left(30, \frac{N(N-1)}{2} \right)$
- $1 \leq K \leq 10^9$
- $1 \leq u_i \lt v_i \leq N$
- The given graph is simple.
Sample Input 1
4 3 2
1 2
2 4
2 3
Sample Output 1
2
Here are the two ways to satisfy the condition.
- Write 1 on vertices 1, 3, 4, and write 2 on vertex 2.
- Write 1 on vertex 2, and write 2 on vertex 1, 3, 4.
Sample Input 2
4 0 10
Sample Output 2
10000
All 10^4 ways satisfy the condition.
Sample Input 3
5 10 5
3 5
1 3
1 2
1 4
3 4
2 5
4 5
1 5
2 3
2 4
Sample Output 3
120
Sample Input 4
5 6 294
1 2
2 4
1 3
2 3
4 5
3 5
Sample Output 4
838338733
Sample Input 5
7 12 1000000000
4 5
2 7
3 4
6 7
3 5
5 6
5 7
1 3
4 7
1 5
2 3
3 6
Sample Output 5
418104233
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分