#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
using ll = long long;
ll INF = 2e18;
template<typename T> using vc = vector<T>;
template<typename T> using vv = vc<vc<T>>;
using vi = vc<int>; using vvi = vv<int>;
using vl = vc<ll>; using vvl = vv<ll>;
using vs = vc<string>; using vvs = vv<string>;
using vb = vc<bool>; using vvb = vv<bool>;
using vmint = vc<mint>; using vvmint = vv<mint>;
#define rep(i,n) for(ll i=0; i<(n); i++)
#define drep(i,n) for(ll i=(n)-1; i>=0; i--)
#define rrep(i,n) for(ll i=1; i<=(n); i++)
#define nfor(i,a,b) for(ll i=a;i<b;i++)
#define dfor(i,a,b) for(ll i=(a)-1; i>=(b); i--)
template<class T>istream& operator>>(istream& i, vc<T>& v) {rep(j,(ll) size(v))i >> v[j]; return i; }
#define nall(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
template<class T> bool chmax(T& a, const T& b){ if(a < b){ a = b; return 1; } return 0; }
template<class T> bool chmin(T& a, const T& b){ if(a > b){ a = b; return 1; } return 0; }
#define YES cout<<"Yes"<<endl
#define NO cout<<"No"<<endl
#define YN {YES;}else{NO;}
#define ERROR cout<<-1<<endl
void print(long double x){ printf("%.20Lf\n",x);}
#define vc_cout(v){ll n = size(v);rep(i,n)cout<<v[i]<<endl;}
#define vv_cout(v){ll n = size(v);rep(i,n){rep(j,size(v[i])){cout<<' '<<v[i][j];}cout<<endl;}}



int main(){
    ll N, M;
    cin >> N >> M;
    vvl edg(N);
    rep(i,M) {
        ll u,v;
        cin >> u >> v;
        u--,v--;
        edg[u].push_back(v);
        edg[v].push_back(u);
    }
    ll K;
    cin >> K;
    vi A(N);
    rep(i,K) {
        ll a;
        cin >> a;
        A[a-1] = 1;
    }
    vvl dis(5, vl(N, INF));
    dis[0][0] = 0;
    queue<pair<int,int>> q;
    q.push({0, 0});

    while (!q.empty()) {
        auto [l, v] = q.front(); q.pop();
        ll dv = dis[l][v];

        for (ll nv : edg[v]) {
            int nl;
            if (A[nv]) {
                if (l == 4) continue;
                nl = l + 1;
            } else {
                nl = 0;
            }
            if (dis[nl][nv] != INF) continue;
            dis[nl][nv] = dv + 1;
            q.push({nl, (int)nv});
        }
    }

    ll ans = INF;
    rep(i,5) chmin(ans, dis[i][N-1]);
    if (ans == INF) ERROR;
    else cout << ans << endl;

}