#include <bits/stdc++.h>
using namespace std;
template <typename P, typename Q>
ostream& operator<<(ostream& os, pair<P, Q> p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}
template <typename P, typename Q>
istream& operator>>(istream& is, pair<P, Q>& p) {
  is >> p.first >> p.second;
  return is;
}
template <typename T>
ostream& operator<<(ostream& os, vector<T> v) {
  os << "(";
  for (auto& i : v) os << i << ",";
  os << ")";
  return os;
}
template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
  for (auto& i : v) is >> i;
  return is;
}
template <typename T>
ostream& operator<<(ostream& os, set<T> s) {
  os << "#{";
  for (auto& i : s) os << i << ",";
  os << "}";
  return os;
}
template <typename K, typename V>
ostream& operator<<(ostream& os, map<K, V> m) {
  os << "{";
  for (auto& i : m) os << i << ",";
  os << "}";
  return os;
}
template <typename T>
inline T setmax(T& a, T b) {
  return a = std::max(a, b);
}
template <typename T>
inline T setmin(T& a, T b) {
  return a = std::min(a, b);
}
template <typename P, typename Q>
inline pair<Q, P> reverse(pair<P, Q> p) {
  return make_pair(p.second, p.first);
}
using lli = long long int;
using ull = unsigned long long;
using point = complex<double>;
using str = string;
template <typename T>
using vec = vector<T>;
constexpr lli mod = 1e9 + 7;
template <typename T>
struct SegTree {
  int n;
  vector<T> dat;
  using F = function<T(T, T)>;
  F fn;
  T e;
  SegTree(int n_, T e_, F fn_) {
    e = e_;
    fn = fn_;
    n = 1;
    while (n < n_) n *= 2;
    dat.resize(2 * n - 1, e);
  }
  void update(size_t k, T a) {
    k += n - 1;
    dat[k] = a;
    while (k > 0) {
      k = (k - 1) / 2;
      dat[k] = fn(dat[k * 2 + 1], dat[k * 2 + 2]);
    }
    return;
  }
  T query(size_t a, size_t b) { return query(a, b, 0, 0, n); }
  T query(size_t a, size_t b, size_t k, size_t l, size_t r) {
    if (r <= a || b <= l) return e;
    if (a <= l && r <= b) return dat.at(k);
    T vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
    T vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
    return fn(vl, vr);
  }
};
int main(int argc, char* argv[]) {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, m, k;
  while (cin >> n >> m >> k) {
    vector<int> a(k);
    cin >> a;
    for (auto& i : a) --i;
    const int N = 2 * 1e5 + 5;
    vector<int> g[N];
    for (int i = 0; i < m; ++i) {
      int x, y;
      cin >> x >> y;
      --x;
      --y;
      g[x].push_back(y);
      g[y].push_back(x);
    }
    const int inf = 1 << 29;
    auto bfs = [&](int src) {
      vector<int> cost(n, inf);
      queue<int> q;
      cost[src] = 0;
      for (q.push(src); q.size(); q.pop()) {
        int curr = q.front();
        for (auto& next : g[curr]) {
          if (cost[next] == inf) {
            cost[next] = cost[curr] + 1;
            q.push(next);
          }
        }
      }
      return cost;
    };
    vector<int> d1 = bfs(0);
    vector<int> d2 = bfs(n - 1);
    sort(a.begin(), a.end(), [&](int i, int j) { return d1[i] < d1[j]; });
    SegTree<int> rmq(a.size(), -(1 << 29),
                     [](int a, int b) { return max(a, b); });
    for (int i = 0; i < a.size(); ++i) {
      rmq.update(i, d2[a[i]]);
    }
    int mx = 0;
    for (int i = 0; i < a.size(); ++i) {
      int x = rmq.query(i + 1, a.size());
      setmax(mx, d1[a[i]] + x + 1);
    }
    cout << min(mx, d1[n - 1]) << endl;
  }
  return 0;
}
