#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T> bool maximize(T &a, const T &b){ return (a < b ? a = b, 1 : 0); }
template<class T> bool minimize(T &a, const T &b){ return (a > b ? a = b, 1 : 0); }
#define fi first
#define se second
#define pb push_back
#define ii pair<int, int>
#define all(x) x.begin(), x.end()
#define TASK "nonsense"
/// end of template ///
const int N = 1e5 + 15;
const int M = 2e5 + 25;
const int Q = 1e5 + 15;
int numNode,numState,numQuery,query[Q],state[M];
vector<ii> adj[N];
ii edge[N];
namespace sub1
{
bool check()
{
return (numQuery==1);
}
bool cmp(ii x, ii y)
{
return x.fi>y.fi;
}
int lst[N];
vector<ii> t[N];
int dfs(int u, int pa, int time)
{
// cout<<u<<' '<<pa<<' '<<time<<'\n';
int ans=0;
for (ii p : adj[u])
{
int v=p.fi,id=p.se;
if (v==pa) continue;
auto it=lower_bound(all(t[id]),make_pair(time,INT_MIN),cmp);
int cm=INT_MIN;
if (it!=t[id].end()) maximize(cm,(*it).fi);
if (it!=t[id].begin())
{
--it;
if (time>=(*it).se) maximize(cm,time);
}
if (cm!=INT_MIN) ans+=1+dfs(v,u,cm);
}
return ans;
}
void solve()
{
memset(lst,-1,sizeof(lst));
for (int tri=1; tri<=numState; ++tri)
{
int x=state[tri];
if (lst[x]==-1) lst[x]=tri;
else
{
t[x].pb(make_pair(tri-1,lst[x]));
lst[x]=-1;
}
}
for (int i=1; i<numNode; ++i)
{
if (lst[i]!=-1) t[i].pb(make_pair(numState,lst[i]));
reverse(all(t[i]));
}
// for (int i=1; i<numNode; ++i)
// {
// for (ii cm : t[i]) cout<<cm.fi<<' '<<cm.se<<'\n';
// cout<<'\n';
// }
cout<<dfs(query[1],-1,numState)+1;
}
}
void solve()
{
cin>>numNode>>numState>>numQuery;
for (int i=1; i<numNode; ++i)
{
int u,v; cin>>u>>v;
edge[i]={u,v};
adj[u].pb({v,i});
adj[v].pb({u,i});
}
for (int i=1; i<=numState; ++i) cin>>state[i];
for (int i=1; i<=numQuery; ++i) cin>>query[i];
if (sub1::check()) return void(sub1::solve());
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// freopen(TASK".inp","r",stdin);
// freopen(TASK".out","w",stdout);
int testcase=1;
// cin>>testcase;
while (testcase--)
solve();
// #define TIME (1.0 * clock() / CLOCKS_PER_SEC)
// cerr << "Time elapsed: " << TIME << " s.\n";
return 0;
}
