#include<bits/stdc++.h>
//入力系
#define cinll(...) ll __VA_ARGS__; input(__VA_ARGS__);
#define cinint(...) int __VA_ARGS__; input(__VA_ARGS__);
#define cinstr(...) string __VA_ARGS__; input(__VA_ARGS__);
#define cinchar(...) char __VA_ARGS__; input(__VA_ARGS__);
#define cindouble(...) double __VA_ARGS__; input(__VA_ARGS__);
#define cinvll(a,n) vll a(n); rep(i,n) cin>>a[i];
#define cinvvll(a,n,m) vvll a(n,vll(m)); rep(i,n) rep(j,m) cin>>a[i][j];
#define cinvs(a,n) vs a(n); rep(i,n) cin>>a[i];
#define cinvpll(a,n) vpll a(n); rep(i,n) cin>>a[i].fst>>a[i].snd;
//繰り返し系
#define rep1(n) for(ll i=0;i<n;i++)
#define rep2(i,n) for(ll i=0;i<n;i++)
#define rep3(i,a,n) for(ll i=a;i<n;i++)
#define rep4(i,a,n,b) for(ll i=a;i<n;i+=b)
#define overload4(a,b,c,d,e,...) e
#define rep(...) overload4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define mrep1(n) for(ll i=n;i>=0;i--)
#define mrep2(i,n) for(ll i=n;i>=0;i--)
#define mrep3(i,n,a) for(ll i=n;i>=a;i--)
#define mrep4(i,n,a,b) for(ll i=n;i>=a;i-=b)
#define mrep(...) overload4(__VA_ARGS__,mrep4,mrep3,mrep2,mrep1)(__VA_ARGS__)
//iterator系
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
//書くのが長いやつ
#define fst first
#define snd second
#define cvvll1(name,a,b) vvll name(a, vll(b))
#define cvvll2(name,a,b,c) vvll name(a, vll(b,c))
#define cvvlloverload2(name,a,b,c,d,...) d
#define make_vvll(...) cvvlloverload2(__VA_ARGS__,cvvll2,cvvll1)(__VA_ARGS__)
using namespace std;
//型系
using ll = long long;
using vll = vector<long long>;
using vvll = vector<vector<long long>>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vb = vector<bool>;
using vvb = vector<vector<bool>>;
using vd = vector<double>;
using vvd = vector<vector<double>>;
using vc = vector<char>;
using vvc = vector<vector<char>>;
using vs = vector<string>;
using pll = pair<long long,long long>;
using pi = pair<int,int>;
using pd = pair<double,double>;
using sll = set<long long>;
using vsll = vector<set<long long>>;
using vpll = vector<pair<long long,long long>>;
using vpi = vector<pi>;
using vpd = vector<pair<double, double>>;
using vvpll  = vector<vector<pair<long long, long long>>>;
#define vmll vector<mll>
#define vvmll vector<vector<mll>>

const ll mod = 998244353LL;
//const ll mod = 1000000007LL;
const ll inf = 1300100100100100100LL;
const double PI=3.1415926535897932384626433832795028841971;

//表示
#define overload1(a,b,NAME,...) NAME
#define coutYesReturn() do {coutYes(); return 0; } while(0)
#define coutYesReturnIf(a) do { if(a){ coutYesReturn(); }} while(0)
#define coutNoReturn() do {coutNo(); return 0;} while(0)
#define coutNoReturnIf(a) do {if(a){ coutNoReturn(); }} while(0)
#define coutReturnIf(a,s) do{if(a){cout<<s<<endl; return 0;}}while(0)
template<typename... T>
void coutll(T... a){ ((cout << a <<" "),...) << endl; }
void coutvll(vll &a){ rep(i,a.size()) cout<<a[i]<<" "; cout<<endl; }
void coutvll(string name, vll &a){ cout<<name<<":"; coutvll(a); }
void coutvlln(vll &a){ rep(i,a.size()) cout<<a[i]<<endl; }
void coutYes(){ cout<<"Yes"<<endl; }
void coutNo(){ cout<<"No"<<endl; }
void coutYesNo(bool a){ cout<<(a?"Yes":"No")<<endl; }
void coutIf(bool a, string s, string t){ cout<<(a?s:t)<<endl; }
//入力
template<class... T>
void input(T&... a){
    (cin >> ... >> a);
}
//複数ソート
template<class... T>
void sorts(vector<T>&... a){
    (sort(all(a)),...);
}
//便利関数
template<typename T> bool chmax(T &a, T b){ if(a < b) {a = b; return true;} return false; }
template<typename T> bool chmin(T &a, T b){ if(a > b) {a = b; return true;} return false; }

//配列表示用
template <typename T>
std::ostream& operator<<(std::ostream& os, const std::vector<T>& vec) { 
    rep(i,vec.size()) os << vec[i] << (i==(ll)vec.size()-1?"":" ");
    return os;
}

int main(){
    cinll(n, m);
    auto to_hash = [&](ll a, ll b){
        return a*n + b;
    };
    vvll tnexts(n);
    rep(i,m){
        cinll(u, v);
        u--; v--;
        tnexts[v].push_back(u);
        tnexts[u].push_back(v);
    }
    cinll(k);
    vb exists_iwi(n, false);
    rep(i,k){
        cinll(a);
        a--;
        exists_iwi[a] = true;
    }
    
    vvll nexts(n*5);
    // 今まで連続してi人いて、場所jにいる時に行ける場所
    rep(i, 5) rep(j, n){
        // 岩井星人がいる時は、+1人して次に行く
        if(exists_iwi[j]){
            if(i < 4) for(ll next: tnexts[j]) nexts[to_hash(i,j)].push_back(to_hash(i+1, next));
        }
        else{
            for(ll next: tnexts[j]) nexts[to_hash(i,j)].push_back(to_hash(0, next));
        }
    }

    //型を入力
    queue<ll> q;
    
    //ここでスタート地点を入れてく
    q.push(0);

    vll min_dists(n*5, inf);
    min_dists[0] = 0;

    while(!q.empty()){
        ll now = q.front();
        q.pop();

        //ここで次の奴らを追加していく
        for(ll next: nexts[now]) if(min_dists[next] == inf){
            min_dists[next] = min_dists[now]+1;
            q.push(next);
        }
    }

    ll ans = inf;
    rep(i,5) chmin(ans, min_dists[to_hash(i, n-1)]);

    if(ans == inf) cout << "-1" << endl;
    else cout << ans << endl;
    
    return 0;
}