#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
#include <string>
#include <functional>
#include <vector>
#include <deque>
#include <utility>
#include <bitset>
#include <limits.h>
using namespace std;
typedef long long ll;
typedef unsigned long long llu;
const int INF = 987654321;
const ll LINF = 1e15;
const int N_ = 200005;
const int M_ = 200005;
const int Q_ = N_;
int TIME, chk[N_];
int N, M, Q;
vector<int> Gph[N_];
int C[Q_], D[Q_], X[N_], Y[N_];
int parent[N_];
void DFS1 (int u) {
int i;
chk[u] = TIME;
for(i = 0; i < Gph[u].size(); i++) {
int v = Gph[u][i];
if(chk[v] != TIME) {
parent[v] = u;
DFS1(v);
}
}
}
bool change[N_];
void DFS2 (int u) {
chk[u] = TIME;
for(int i = 0; i < Gph[u].size(); i++) {
int v = Gph[u][i];
if(chk[v] != TIME && change[v]) DFS2(v);
}
}
int main() {
int i, j, k;
scanf("%d%d%d", &N, &M, &Q);
for(i = 1; i < N; i++) {
int u, v; scanf("%d%d", &u, &v);
Gph[u].push_back(v);
Gph[v].push_back(u);
X[i] = u; Y[i] = v;
}
for(i = 1; i <= M; i++) scanf("%d", D+i);
for(i = 1; i <= Q; i++) scanf("%d", C+i);
if(Q == 1) {
int r = C[1];
++TIME; DFS1(r);
for(i = 1; i <= M; i++) {
int &d = D[i];
if(X[d] == parent[Y[d]]) d = Y[d];
else d = X[d];
}
++TIME;
for(i = 1; i <= M; i++) change[D[i]] ^= true;
DFS2(r);
for(i = M; i > 0; i--) {
int &d = D[i];
change[d] ^= true;
if(change[d] && chk[parent[d]] == TIME && chk[d] != TIME) DFS2(d);
}
int ret = 0;
for(i = 1; i <= N; i++) {
if(chk[i] == TIME) ++ret;
}
printf("%d\n", ret);
}else {
}
return 0;
}
