#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
using ar2 = array<int,2>;
const int N = (int)2e5+10;
int n, m, q;
vector<int> adj[N];
vector<ar2> edges;
set<int> S[N];
int st[N], dfs_timer;
int e[N], r[N], active[N];
void dfs(int s, int p){
st[s] = dfs_timer++;
for(auto u : adj[s]){
if(u==p) continue;
dfs(u,s);
}
}
int dfs2(int s, int p, int curT){
int ans = 1;
for(auto u : adj[s]){
if(u==p) continue;
auto itr = S[u].upper_bound(curT);
if(itr==begin(S[u])) continue;
itr--; ans+=dfs2(u,s,*itr);
}
return ans;
}
int32_t main(){
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> m >> q;
for(int i = 1; i < n; i++){
int a, b; cin >> a >> b;
a--, b--;
adj[a].pb(b); adj[b].pb(a);
edges.pb({a,b});
}
for(int i = 0; i < m; i++) cin >> e[i], e[i]--;
for(int i = 0; i < q; i++) cin >> r[i], r[i]--;
dfs(r[0],-1); S[r[0]].insert(m*2);
for(int i = 0; i < m; i++){
auto [a,b] = edges[e[i]];
if(st[a]<st[b])swap(a,b);
active[e[i]]^=1;
if(!active[e[i]]) S[a].insert(i-1);
else S[a].insert(i);
}
for(int i = 0; i < n-1; i++){
auto [a,b] = edges[i];
if(st[a]<st[b]) swap(a,b);
if(active[i]) S[a].insert(m);
}
cout << dfs2(r[0],-1,*prev(end(S[r[0]]))) << "\n";
}
