#include <bits/stdc++.h>
#define ll long long
#define pii pair <int, int>
#define fi first
#define se second
#define pb push_back
#define int long long
#define lowbit(x) ((x)&-(x))

using namespace std;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
const int N = 5e5+5, mod = 998244353; 
int n, v[N], vis[N], dfn[N], sz[N], a[N], dt, ld[N], rd[N], k; 
vector <int> e[N]; 
ll qpow (ll x, ll y = mod-2) {
	ll res = 1;
	while (y) {
		if (y&1) res = res*x%mod;
		x = x*x%mod; y >>= 1;
	}
	return res; 
}
void dfs (int p, int fa) {
	sz[p] = vis[p]; 
	for (int i : e[p]) {
		if (i == fa) continue; 
		dfs(i, p); sz[p] += sz[i]; 
	}
	sort(e[p].begin(), e[p].end(), [&](int x, int y) { return sz[x] < sz[y]; });
}
void tdfs (int p, int fa) {
	ld[p] = dt+1;
	if (vis[p]) dfn[p] = ++dt; 
	for (int i : e[p]) {	
		if (i == fa) continue; 
		tdfs(i, p); 
	} 
	rd[p] = dt; 
}
ll ans = 1; 
ll sk[N], f[N], g[N], tmp[N]; 
ll td[N]; 
void dfs2 (int p, int fa, int k) {
	if (vis[p]) {
//		cout << p << " " << v[p] << " " << k << endl; 	
		g[dfn[p]] = (v[p]+k)%mod;
		ans = ans*(v[p]+k)%mod; 
		sk[dfn[p]] = 1; 
		for (int j : e[p]) {
			if (j == fa || !sz[j]) continue; 
			dfs2(j, p, -v[p]);  
		}
		for (int j = ld[p]+1;j <= rd[p];j++) sk[j] = 0; 
		return; 
	}
	ll s = 0; 
	for (int i : e[p]) {
		if (i == fa || !sz[i]) continue; 
		dfs2(i, p, k);  
		tmp[i] = (1-s)%mod; 
		td[i] = (v[p]+k)%mod; 
		ll tk = k; 
		for (int j = ld[i];j <= rd[i];j++) {
			ll sv = qpow(g[j])*td[i]%mod; 
			(k -= (v[p]+tk)%mod*sv%mod*sk[j]%mod) %= mod; (s += sv*sk[j]%mod*tmp[i]) %= mod; 
		}
	}
	ll st = 0; 
	for (int I = 1l*e[p].size()-1; ~I; I--) {
		int i = e[p][I]; 
		if (i == fa || !sz[i]) continue; 
		ll ts = 0; 
		for (int j = ld[i];j <= rd[i];j++) (ts += qpow(g[j])*sk[j]) %= mod; 
		for (int j = ld[i];j <= rd[i];j++) (sk[j] = (1-tmp[i]-st*td[i])%mod*sk[j]) %= mod; 
		(st += ts*(1-tmp[i]-st*td[i]%mod)%mod) %= mod; 
	}
}

void solve () {
	cin >> n >> k; 
	for (int i = 1;i <= n;i++) cin >> v[i]; 
	for (int i = 1;i <= k;i++) {
		cin >> a[i]; 
		if (vis[a[i]]) {
			cout << "0"; return; 
		}
		vis[a[i]] = 1;
	}
	for (int i = 1;i < n;i++) {
		int x, y; cin >> x >> y; 
		e[x].pb(y); e[y].pb(x); 
	}
	dfs(1, 0); tdfs(1, 0); 
	dfs2(1, 0, 0);  
	if (ans < 0) ans += mod; 
	cout << ans;
}

signed main () {
//	ios::sync_with_stdio(0);
//	cin.tie(0); cout.tie(0);
	int T = 1;
	while (T--) solve();
	return 0;
}