Problem Statement
There is a tree $T$ with $N$ vertices numbered from $1$ to $N$. The $i$-th edge connects vertices $u_i$ and $v_i$. Additionally, vertex $i$ is painted with color $A_i$.
Find the number, modulo $998244353$, of (non-empty) subsets $S$ of the vertex set of $T$ that satisfy the following condition:
- The induced subgraph
$G$of$T$by$S$satisfies all of the following conditions: $G$is a tree.- All vertices with degree
$1$have the same color.
- All vertices with degree
What is an induced subgraph? Let $S$ be a subset of the vertices of a graph $G$. The induced subgraph of $G$ by $S$ is a graph whose vertex set is $S$ and whose edge set consists of all edges in $G$ that have both endpoints in $S$.
Constraints
$1 \leq N \leq 2 \times 10^5$$1 \leq A_i \leq N$$1 \leq u_i \lt v_i \leq N$- The graph given in the input is a tree.
- All input values are integers.
Input
The input is given from Standard Input in the following format:
N
A_1 A_2 \dots A_N
u_1 v_1
u_2 v_2
\vdots
u_{N-1} v_{N-1}
Output
Print the number, modulo $998244353$, of (non-empty) subsets $S$ of the vertex set of $T$ that satisfy the condition in the problem statement.
样例
3
1 2 1
1 2
2 3
4
5
2 2 1 1 1
2 5
3 4
1 3
1 5
9
15
5 3 5 1 1 4 4 4 2 5 5 4 4 2 5
3 13
4 10
7 11
8 9
2 10
2 14
5 11
5 6
6 13
12 13
9 14
9 13
1 13
1 15
48
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