#include<bits/stdc++.h>
using std::cin;
using std::cout;
const int N = 300005;
using u64 = unsigned long long;

const int mod = 998244353;
const int inv2 = (mod + 1) / 2;
struct func { int k, a; };
func operator + (func x, func y) {
	return {(u64) x.k * y.k % mod, ((u64) x.a * y.k + y.a) % mod};
}

func v[N][2];
int pow(int a, int b, int ans = 1) {
	for(;b;b >>= 1, a = (u64) a * a % mod) if(b & 1)
		ans = (u64) ans * a % mod;
	return ans;
}

struct ds {
	int mul, cnt;
	ds() { mul = 1, cnt = 0; }
	void ins(int x) {
		++ x;
		if(x) mul = (u64) mul * x % mod;
		else ++cnt;
	}
	void del(int x) {
		++ x;
		if(x) mul = pow(x, mod-2, mul);
		else --cnt;
	}
	func v() const {
		int w = cnt ? 0 : mul;
		return {w, w};
	}
} pb[N];

int son[N][2], fa[N], rev[N];
int get(int x, int p = 1) { return son[fa[x]][p] == x; }
int isroot(int x) { return !(get(x) || get(x, 0)); }

void update(int x) {
	func z = pb[x].v();
	v[x][0] = z;
	v[x][1] = z;
	if(son[x][0]) {
		v[x][0] = v[son[x][0]][0] + v[x][0];
		v[x][1] = v[x][1] + v[son[x][0]][1];
	}
	if(son[x][1]) {
		v[x][0] = v[x][0] + v[son[x][1]][0];
		v[x][1] = v[son[x][1]][1] + v[x][1];
	}
}

void rotate(int x) {
	int y = fa[x], z = fa[y], b = get(x);
	if(!isroot(y)) son[z][get(y)] = x;
	son[y][b] = son[x][!b], son[x][!b] = y;
	fa[son[y][b]] = y, fa[y] = x, fa[x] = z;
	update(y);
}
void put(int x) {
	std::swap(son[x][0], son[x][1]);
	std::swap(v[x][0], v[x][1]);
	rev[x] ^= 1;
}
void pushdown(int x) {
	if(rev[x]) {
		put(son[x][0]);
		put(son[x][1]);
		rev[x] = 0;
	}
}
void down(int x) {
	if(!isroot(x)) down(fa[x]);
	pushdown(x);
}
void splay(int x) {
	for(;!isroot(x);rotate(x)) if(!isroot(fa[x]))
		rotate(get(x) ^ get(fa[x]) ? x : fa[x]);
	update(x);
}
int out(int x) {
	return v[x][1].a;
}
void access(int x) {
	for(int t = 0;x;) {
		splay(x);
		if(son[x][1]) pb[x].ins(out(son[x][1]));
		if(t) pb[x].del(out(t));
		son[x][1] = t;
		update(x);
		t = x;
		x = fa[x];
	}
}
void makeroot(int x) {
	access(x), splay(x), put(x);
}
int n;
int a[N];
std::vector<int> go[N];
int vis[N], rk[N];
int ans = 0, sum = 0;
int main() {
	std::ios::sync_with_stdio(false), cin.tie(0);
	cin >> n;
	for(int i = 1;i <= n;++i) cin >> a[i], update(i), rk[i] = i;
	for(int i = 1, u, v;i < n;++i) {
		cin >> u >> v;
		go[u].push_back(v);
		go[v].push_back(u);
	}
	for(int i = 1;i <= n;++i) pb[i].ins(pow(inv2, go[i].size() - 1) - 1);
	std::sort(rk + 1, rk + n + 1, [](int x, int y) {
		return a[x] < a[y];
	});
	const int T = pow(2, n - 2);
	for(int i = n;i >= 1;--i) {
		int x = rk[i];
		for(int t : go[x]) if(vis[t]) {
			makeroot(t);
			pb[x].ins(out(t));
			fa[t] = x;
		}
		update(x);
		sum = (sum + out(x)) % mod;
//		cout << (u64) out(x) * T %mod << '\n';
		ans = (ans + (u64) (a[rk[i]] - a[rk[i - 1]]) * sum) % mod;
		vis[x] = 1;
	}
	ans = (u64) ans * T % mod;
	cout << ans << '\n';
}