#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define x first
#define y second
ll N, M, K;
pair<ll, ll> E[200005];
vector<pair<ll, ll>> G[200005];
ll dist[200005];
const ll INF = 1e18;
ll deg[200005];
ll chk[200005];
int main(){
cin.tie(0) -> sync_with_stdio(false);
cin >> N >> M >> K;
for(int i = 1; i <= M; i++){
cin >> E[i].x >> E[i].y;
G[E[i].x].push_back({E[i].y, i});
G[E[i].y].push_back({E[i].x, i});
}
queue<ll> Q;
fill(dist, dist + N + 1, INF);
Q.push(1); dist[1] = 0;
while(!Q.empty()){
ll u = Q.front(); Q.pop();
for(auto i : G[u]){
if(dist[i.x] <= dist[u] + 1) continue;
dist[i.x] = dist[u] + 1;
Q.push(i.x);
}
}
for(int i = 1; i <= M; i++){
if(dist[E[i].x] == dist[E[i].y]) continue;
if(dist[E[i].x] > dist[E[i].y]) swap(E[i].x, E[i].y);
deg[E[i].y]++;
}
ll r = 0;
while(K--){
ll t; cin >> t;
if(!chk[t] && dist[E[t].x] != dist[E[t].y]){
Q.push(t); chk[t] = 1;
while(!Q.empty()){
ll u = Q.front(); Q.pop();
deg[E[u].y]--;
if(deg[E[u].y] == 0){
r++;
for(auto i : G[E[u].y]){
if(chk[i.y] || dist[E[i.y].x] == dist[E[i.y].y]) continue;
chk[i.y] = 1;
Q.push(i.y);
}
}
}
}
cout << r << '\n';
}
}
