#include<bits/stdc++.h>
#define int long long
#define rep(i,j,k) for(int i=j;i<=k;i++)
using namespace std;
const int N=5e5+5,mod=998244353;
int n,k,val[N],vis[N],f[N],g[N];
vector<int> v[N];
void dfs(int x,int fa){
    int c0=1,c1=0;
    for(auto dq:v[x]) if(dq!=fa){dfs(dq,x); int d0=(c0*f[dq]+c0*g[dq]%mod*(mod-val[x]))%mod,d1=(c1*f[dq]+(c0+c1*val[x])%mod*g[dq]%mod*(mod-1))%mod; c0=d0,c1=d1;}
    if(vis[x]) f[x]=c0*val[x]%mod,g[x]=c0; 
    else f[x]=(c0-val[x]*c1%mod+mod),g[x]=mod-c1;
}
signed main(){
    ios::sync_with_stdio(false);
    cin>>n>>k;
    rep(i,1,n) cin>>val[i];
    rep(i,1,k){
        int x; cin>>x;
        if(vis[x]){cout<<0; return 0;} vis[x]=1;
    }
    rep(i,1,n-1){int u,vv; cin>>u>>vv,v[u].push_back(vv),v[vv].push_back(u);}
    dfs(1,0),cout<<f[1];
}