#include <bits/stdc++.h>
using namespace std;
void fun() {}
long long int md = 998244353;
long long int __gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return __gcd(b, a % b);
}
long long int poww(long long int a, long long int b, long long int md) {
  if (b < 0) return 0;
  if (a == 0) return 0;
  long long int res = 1;
  while (b) {
    if (b & 1) {
      res = (1ll * res * a) % md;
    }
    a = (1ll * a * a) % md;
    b >>= 1;
  }
  return res;
}
long long int poww(long long int a, long long int b) {
  if (b < 0) return 0;
  if (a == 0) return 0;
  long long int res = 1;
  while (b) {
    if (b & 1) {
      res = (1ll * res * a);
    }
    a = (1ll * a * a);
    b >>= 1;
  }
  return res;
}
void ainp(long long int arr[], long long int n) {
  for (long long int i = 1; i <= n; i++) cin >> arr[i];
}
void disp(long long int arr[], long long int n) {
  for (long long int i = 1; i <= n; i++) cout << arr[i] << " ";
  cout << "\n";
}
void dispv(vector<long long int> &v) {
  for (long long int i = 0; i < v.size(); i++) cout << v[i] << " ";
  cout << "\n";
}
long long int divide(long long int a, long long int b, long long int md) {
  long long int rr = a * (poww(b, md - 2, md));
  rr %= md;
  return rr;
}
const long long int size = 2e5 + 5;
long long int n, m, k, u, v;
vector<long long int> g[size];
pair<long long int, long long int> dis[size], prr[size];
queue<long long int> q;
long long int arr[size], suffmax[size];
bool fnn(pair<long long int, long long int> &p1,
         pair<long long int, long long int> &p2) {
  return (p1.first - p1.second < p2.first - p2.second);
}
void bfs() {
  dis[1].first = 0;
  q.push(1);
  while (!q.empty()) {
    long long int node = q.front();
    q.pop();
    for (long long int child : g[node]) {
      if (dis[child].first > dis[node].first + 1 ||
          (child != 1 && dis[child].first == 0)) {
        dis[child].first = dis[node].first + 1;
        q.push(child);
      }
    }
  }
  q.push(n);
  dis[n].second = 0;
  while (!q.empty()) {
    long long int node = q.front();
    q.pop();
    for (long long int child : g[node]) {
      if (dis[child].second > dis[node].second + 1 ||
          (child != n && dis[child].second == 0)) {
        dis[child].second = dis[node].second + 1;
        q.push(child);
      }
    }
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  fun();
  cin >> n >> m >> k;
  ainp(arr, k);
  for (long long int i = 1; i <= m; i++) {
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  bfs();
  for (long long int i = 1; i <= k; i++) prr[i] = dis[arr[i]];
  sort(prr + 1, prr + 1 + k, fnn);
  for (long long int i = k; i > 0; i--)
    suffmax[i] = max(suffmax[i + 1], prr[i].second);
  long long int cost = dis[n].first;
  long long int cst = 0;
  for (long long int i = 1; i < k; i++) {
    cst = max(suffmax[i + 1] + 1 + prr[i].first, cst);
  }
  cout << min(cst, cost) << "\n";
  return 0;
}
