#include <atcoder/all>
#include <bits/stdc++.h>

using namespace std;
using namespace atcoder;

using ll = long long;
using ld = long double;

ll INF = 2e18;

template<typename T> using vc = vector<T>;
template<typename T> using vv = vc<vc<T>>;

#define MP(a, b) make_pair(a, b)
#define nfor(i,s,n) for(ll i=s;i<(ll)n;i++)
#define rep(i,n) for(ll i = 0; i < (n); i++)

using vl = vc<ll>; using vvl = vv<ll>; using vvvl = vv<vl>; using vvvvl = vv<vvl>;
using vs = vc<string>; using vvs = vv<string>;
using vb = vc<bool>; using vvb = vv<bool>; using vvvb = vv<vb>;
using vld = vc<ld>; using vvld = vv<ld>; using vvvld = vv<vld>;
using P = pair<ll, ll>;
template<class T>istream& operator>>(istream& i, vc<T>& v) { rep(j, size(v))i >> v[j]; return i; }
template<class T> using pq = priority_queue<T, vc<T>>;//大きい順
template<class T> using pq_g = priority_queue<T, vc<T>, greater<T>>;//小さい順


#define pb push_back
#define pob pop_back
#define all(s) s.begin(),s.end()
#define YES std::cout<<"Yes"<<std::endl
#define NO std::cout<<"No"<<std::endl
#define YN {std::cout<<"Yes"<<std::endl;}else{std::cout<<"No"<<std::endl;}
#define dame std::cout<<-1<<std::endl
#define pop_cnt(s) ll(popcount(uint64_t(s)))
#define yu_qurid(x,y) ((x)*(x)+(y)*(y))
#define mannhattan(x1,x2,y1,y2) (abs(x1-x2)+abs(y1-y2))
#define vc_cout(v){ll n = size(v);rep(i,n)std::cout<<v[i]<<std::endl;}
#define vv_cout(v){ll n = size(v);rep(i,n){rep(j,size(v[i])){std::cout<<v[i][j]<<' ';}std::cout<<std::endl;}}
using mint = atcoder::modint998244353;
// using mint = atcoder::modint1000000007;
using vm = vc<mint>;
using vvm = vc<vm>;

int main(){
    ll n, m;
    cin >> n >> m;
    vvl g(n);
    rep(i, m){
        ll a, b;
        cin >> a >> b;
        a--; b--;
        g[a].pb(b);
        g[b].pb(a);
    }
    vb b(n, false);
    ll k;
    cin >> k;
    rep(i, k){
        ll c;
        cin >> c;
        c--;
        b[c] = true;
    }
    vvl dist(n, vl(5, INF));
    dist[0][0] = 0;
    queue<P> q;
    q.push({0, 0});
    while(!q.empty()){
        auto [v, s] = q.front(); q.pop();
        ll d = dist[v][s];
        for(auto nv : g[v]){
            ll ns = 0;
            if(b[nv]) ns = s + 1;
            if(ns > 4) continue;
            if(dist[nv][ns] > d + 1){
                dist[nv][ns] = d + 1;
                q.push({nv, ns});
            }
        }
    }

    ll ans = INF;
    rep(i, 5) ans = min(ans, dist[n-1][i]);
    if(ans == INF){
        dame;
    }else{
        cout << ans << endl;
    }
}