P24269 [AtCoder] Painting Weighted Graph
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题目描述

Problem Statement

Given is an undirected graph with N vertices and M edges. The i-th edge connects Vertices A_i and B_i and has a weight of C_i.
Initially, all vertices are painted black. You can do the following operation at most K times.

  • Operation: choose any vertex v and any integer x. Paint red all vertices reachable from the vertex v by traversing edges whose weights are at most x, including v itself.

How many sets can be the set of vertices painted red after the operations?
Find the count modulo 998244353.

Input

Input is given from Standard Input in the following format:
N M K
A_1 B_1 C_1
$\vdots$
A_M B_M C_M

Output

Print the answer.

Constraints

  • $2 \leq N \leq 10^5$
  • $0 \leq M \leq 10^5$
  • $1 \leq K \leq 500$
  • $1 \leq A_i,B_i \leq N$
  • $1 \leq C_i \leq 10^9$
  • All values in input are integers.

Sample Input 1

3 2 1
1 2 1
2 3 2

Sample Output 1

6

For example, an operation with (v,x)=(2,1) paints Vertices 1,2 red, and an operation with (v,x)=(1,0) paints Vertex 1.
After at most one operation, the set of vertices painted red can be one of the following six: {},{1},{2},{3},{1,2},{1,2,3}.

Sample Input 2

5 0 2

Sample Output 2

16

The given graph may not be connected.

Sample Input 3

6 8 2
1 2 1
2 3 2
3 4 3
4 5 1
5 6 2
6 1 3
1 2 10
1 1 100

Sample Output 3

40

The given graph may have multi-edges and self-loops.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
3 2 1 1 2 1 2 3 2
样例输出
6