#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<cassert>
#include<set>
#include<random>
#include<chrono>
#include<bitset>
#include<map>
#include<queue>
#include<cstdlib>
#include<cmath>
#include<iostream>
#include<string>
#include<unordered_map>
#define eb emplace_back

using namespace std;
const int maxn=5e5+10, mxsz=1594323+10, inf=1e9+10, P=998244353;
const double eps=1e-10, pi=acos(-1.0);
typedef long long LL;
typedef unsigned long long ULL;
const LL INF=4e18;
typedef pair<LL, int> pli;
typedef pair<int, int> pii;
typedef pair<int, LL> pil;
typedef pair<LL, LL> pll;
inline int read() {
	int x=0, f=1; char c=getchar();
	for(; c<'0'||c>'9'; c=getchar()) if(c=='-') f=0;
	for(; c>='0'&&c<='9'; c=getchar()) x=x*10+c-'0';
	return f?x:-x;
}inline LL readll() {
	LL x=0; int f=1; char c=getchar();
	for(; c<'0'||c>'9'; c=getchar()) if(c=='-') f=0;
	for(; c>='0'&&c<='9'; c=getchar()) x=x*10+c-'0';
	return f?x:-x;
}
mt19937_64 rnd((unsigned)chrono::steady_clock::now().time_since_epoch().count());
inline int ksm(int x, int y) {
	int s=1;
	for(; y; y>>=1, x=1LL*x*x%P)
		if(y&1) s=1LL*s*x%P;
	return s;
}
inline int add(int x, int y) {x+=y; return x>=P?x-P:x;}
inline int del(int x, int y) {x-=y; return x<0?x+P:x;}
inline int abs_(int x) {return x>0?x:-x;}
int gcd(int x, int y) {return y?gcd(y, x%y):x;}

int v[maxn], mrk[maxn];
struct pj{int y, nxt;} g[maxn<<1];
int len, la[maxn];
inline void add_e(int x, int y) {g[++len].y=y; g[len].nxt=la[x]; la[x]=len;}

void dfs(int x, int F) {
	for(int i=la[x]; i; i=g[i].nxt) {
		int y=g[i].y;
		if(y!=F) dfs(y, x);
	}
	v[x]=del(v[x], v[F]);
}

int dp[maxn][2], lst[maxn];
int suf[maxn];
void sol(int x, int F) {
	for(int i=la[x]; i; i=g[i].nxt) {
		int y=g[i].y;
		if(y!=F) sol(y, x);
	}
	if(mrk[x]) {
		int t=1;
		for(int i=la[x]; i; i=g[i].nxt) {
			int y=g[i].y;
			if(y!=F) t=1ll*t*dp[y][0]%P;
		}
		dp[x][0]=1ll*t*v[x]%P;
		dp[x][1]=t;
		return;
	}
	int cnt=0;
	for(int i=la[x]; i; i=g[i].nxt) {
		int y=g[i].y;
		if(y!=F) lst[++cnt]=y;
	}
	if(cnt==0) {
		dp[x][0]=1;
		return;
	}
	suf[cnt+1]=1;
//	printf("cnt=%d\n", cnt);
//	for(int i=1; i<=cnt; ++i) printf("%d ", lst[i]); puts("");
	for(int i=cnt; i>0; --i) suf[i]=1ll*suf[i+1]*dp[lst[i]][0]%P;
//	for(int i=1; i<=cnt+1; ++i) printf("%d ", suf[i]); puts("");
	dp[x][0]=suf[1]; dp[x][1]=0;
//	printf("suf[1]=%d\n", suf[1]);
	int pre=1;
	for(int i=1; i<=cnt; ++i) {
		dp[x][0]=add(dp[x][0], 1ll*pre*dp[lst[i]][1]%P*suf[i+1]%P*v[x]%P);
		dp[x][1]=add(dp[x][1], 1ll*pre*dp[lst[i]][1]%P*suf[i+1]%P);
		pre=1ll*pre*dp[lst[i]][0]%P;
	}
//	printf("dp[%d][0]=%d dp[%d][1]=%d\n", x, dp[x][0], x, dp[x][1]);
}

int main() {
	int n=read(), k=read();
	for(int i=1; i<=n; ++i) v[i]=read();
	for(int i=1; i<=k; ++i) {
		int x=read();
		mrk[x]=1;
	}
	for(int i=1, x, y; i<n; ++i) {
		x=read(), y=read();
		add_e(x, y); add_e(y, x);
	}
	dfs(1, 0);

	sol(1, 0);
	printf("%d", dp[1][0]);
	return 0;
}