#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;
    }
    vvb vis(5,vb(N,0));
    vvl dis(5,vl(N,INF));
    dis[0][0] = 0;
    queue<pair<int,ll>> todo;
    todo.push({0,0});
    while(todo.size()>0) {
        auto [l,v] = todo.front();
        todo.pop();
        vis[l][v] = 1;
        for(ll nv : edg[v]) {
            if(A[nv] == 1) {
                if(l != 4) {
                    if(vis[l+1][nv]) continue;
                    todo.push({l+1,nv});
                    dis[l+1][nv] = dis[l][v]+1;
                }
            } else {
                if(vis[0][nv]) continue;
                todo.push({0,nv});
                dis[0][nv] = dis[l][v]+1;
            }
        }
    }
    ll ans = INF;
    rep(i,5) {
        if(vis[i][N-1]==1) {
            chmin(ans,dis[i][N-1]);
        }
    }
    if(ans == INF) ERROR;
    else cout << ans << endl;
}