#include <stdio.h>

const int Mod = 998244353;

typedef struct Edge {
	struct Edge *next;
	int v, id;
	long long dp[1001];
} edge;

long long div_mod(long long x, long long y, long long z)
{
	if (x % y == 0) return x / y;
	else return (div_mod((1 + x / y) * y - x, (z % y), y) * z + x) / y;
}

int main()
{
	int i, N, M, u, w, A[5001];
	edge *adj[5001] = {}, e[10001], *p;
	scanf("%d", &N);
	for (u = 1; u <= N; u++) scanf("%d", &(A[u]));
	for (i = 0; i < N - 1; i++) {
		scanf("%d %d", &u, &w);
		e[i*2].v = w;
		e[i*2+1].v = u;
		e[i*2].id = i * 2;
		e[i*2+1].id = i * 2 + 1;
		e[i*2].next = adj[u];
		e[i*2+1].next = adj[w];
		adj[u] = &(e[i*2]);
		adj[w] = &(e[i*2+1]);
	}
	
	int par[5001] = {}, pred[5001], q[5001], head, tail;
	q[0] = 1;
	par[1] = 1;
	pred[1] = -1;
	for (head = 0, tail = 1; head < tail; head++) {
		u = q[head];
		for (p = adj[u]; p != NULL; p = p->next) {
			w = p->v;
			if (par[w] == 0) {
				par[w] = u;
				pred[w] = p->id;
				q[tail++] = w;
			}
		}
	}
	
	int k;
	long long sum;
	for (head--; head >= 1; head--) {
		u = q[head];
		i = pred[u];
		
		if (adj[u]->next == NULL) {
			for (k = 0; k < A[u]; k++) e[i].dp[k] = 1;
			for (k = A[u]; k <= 1000; k++) e[i].dp[k] = 2;
			continue;
		}
		
		for (p = adj[u], sum = 1; p != NULL; p = p->next) {
			if (p->v == par[u]) continue;
			sum = sum * p->dp[1000] % Mod;
		}
		e[i].dp[0] = sum;
		for (k = 1; k < A[u]; k++) e[i].dp[k] = e[i].dp[0];
		for (k = A[u]; k <= 1000; k++) {
			for (p = adj[u], sum = 1; p != NULL; p = p->next) {
				if (p->v == par[u]) continue;
				sum = sum * p->dp[k] % Mod;
			}
			e[i].dp[k] = (e[i].dp[0] + sum) % Mod;
		}
	}
	
	long long ans = 0;
	static long long prod[5001][1001];
	for (k = 0; k <= 1000; k++) {
		for (p = adj[1], prod[1][k] = 1; p != NULL; p = p->next) prod[1][k] = prod[1][k] * p->dp[k] % Mod;
		if (k > 0) ans += (prod[1][k] - prod[1][k-1] + Mod) * ((k >= A[1])? k: A[1]) % Mod;
	}
	ans += prod[1][0] * A[1] % Mod;
	for (head = 1; head < tail; head++) {
		w = q[head];
		i = pred[w] ^ 1;
		u = par[w];
		
		if (adj[u]->next == NULL) {
			for (k = 0; k < A[u]; k++) e[i].dp[k] = 1;
			for (k = A[u]; k <= 1000; k++) e[i].dp[k] = 2;
		} else {
			e[i].dp[0] = div_mod(prod[u][1000], e[i^1].dp[1000], Mod);
			for (k = 1; k < A[u]; k++) e[i].dp[k] = e[i].dp[0];
			for (k = A[u]; k <= 1000; k++) e[i].dp[k] = (e[i].dp[0] + div_mod(prod[u][k], e[i^1].dp[k], Mod)) % Mod;
		}

		for (k = 0; k <= 1000; k++) {
			for (p = adj[w], prod[w][k] = 1; p != NULL; p = p->next) prod[w][k] = prod[w][k] * p->dp[k] % Mod;
			if (k > 0) ans += (prod[w][k] - prod[w][k-1] + Mod) * ((k >= A[w])? k: A[w]) % Mod;
		}
		ans += prod[w][0] * A[w] % Mod;
	}
	printf("%lld\n", ans % Mod);
	fflush(stdout);
	return 0;
}