#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

template <class Ss, Ss (*op0)(Ss, Ss), Ss (*e)(), class Sv, Ss (*op1)(Sv, Ss), class Se, Ss (*op2)(Se, Ss)>
struct rerooting{
	
	int n;
	vector<vector<int>> to;
	vector<vector<Se>> edge;
	
	vector<Ss> subtree,answer;
	
	vector<Sv> vertex;
	
	rerooting(int _n){
		n = _n;
		to.resize(n);
		edge.resize(n);
		subtree.resize(n,e());
		answer.resize(n,e());
		vertex.resize(n);
	}
	
	rerooting(vector<Sv> v){
		n = v.size();
		to.resize(n);
		edge.resize(n);
		subtree.resize(n,e());
		answer.resize(n,e());
		vertex = v;
	}
	
	void add_directed_edge(int u,int v,Se x){
		to[u].push_back(v);
		edge[u].push_back(x);
	}
	
	void add_edge(int u,int v,Se x){
		add_directed_edge(u,v,x);
		add_directed_edge(v,u,x);
	}
	
	void solve(){
		dfs(0,-1);
		redfs(0,-1,e());
	}
	
	void dfs(int cur,int par){
		Ss temp = e();
		for(int i=0;i<to[cur].size();i++){
			int nxt = to[cur][i];
			if(nxt==par)continue;
			dfs(nxt,cur);
			temp = op0(temp, op2(edge[cur][i], subtree[nxt]));
		}
		subtree[cur] = op1(vertex[cur], temp);
	}
	
	void redfs(int cur, int par, Ss ps){
		vector<Ss> P(to[cur].size()+1,e());
		rep(i,to[cur].size()){
			int nxt = to[cur][i];
			if(nxt!=par)P[i+1] = op2(edge[cur][i], subtree[nxt]);
			else P[i+1] = op2(edge[cur][i], ps);
		}
		vector<Ss> S(P.rbegin(),P.rend()-1);
		S.insert(S.begin(),e());
		rep(i,to[cur].size()){
			P[i+1] = op0(P[i], P[i+1]);
			S[i+1] = op0(S[i+1], S[i]);
		}
		answer[cur] = op1(vertex[cur], P.back());

		for(int i=0;i<to[cur].size();i++){
			int nxt = to[cur][i];
			if(nxt!=par){
				redfs(nxt,cur,op1(vertex[cur], op0(P[i],S[to[cur].size()-1-i])));
			}
		}
	}
	
};

using A = array<mint,1005>;

A e(){
	A ret;
	rep(i,1005)ret[i] = 0;
	ret[0] = 1;
	return ret;
}

A op0(A a,A b){
	rep(i,1004){
		a[i+1] += a[i];
		b[i+1] += b[i];
	}
	A ret = e();
	ret[0] = 0;
	rep(i,1005){
		if(i==0)ret[i] = a[i]*b[i];
		else{
			ret[i] += (a[i]-a[i-1]) * (b[i]-b[i-1]);
			ret[i] += (a[i]-a[i-1]) * b[i-1];
			ret[i] += a[i-1] * (b[i]-b[i-1]);
		}
	}
	
	return ret;
}


A op1(int a,A b){
	rep(i,a){
		b[a] += b[i];
		b[i] = 0;
	}
	return b;
}

A op2(int a,A b){
	mint s = 0;
	rep(i,1003)s += b[i];
	b[0] += s;
	return b;
}


int main(){
	int n;
	cin>>n;
	vector<int> a(n);
	rep(i,n)cin>>a[i];
	rerooting<A,op0,e,int,op1,int,op2> R(a);
	
	rep(i,n-1){
		int u,v;
		cin>>u>>v;
		R.add_edge(u-1,v-1,1);
	}
	
	R.solve();
	
	mint ans = 0;
	rep(i,n){
		rep(j,1003){
			ans += R.answer[i][j] * j;
		}
	}
	
	cout<<ans.val()<<endl;
	
	return 0;
}