#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define ull unsigned long long
#define ld  long double

using LL = long long; using ULL = unsigned long long;
using VI = vector<int>; using VVI = vector<VI>; using VVVI = vector<VVI>;
using VL = vector<LL>; using VVL = vector<VL>; using VVVL = vector<VVL>;
using VB = vector<bool>; using VVB = vector<VB>; using VVVB = vector<VVB>;
using VD = vector<double>; using VVD = vector<VD>; using VVVD = vector<VVD>;
using VC = vector<char>; using VS = vector<string>; using VVC = vector<VC>;
using PII = pair<int,int>; using PLL = pair<LL,LL>; using PDD = pair<double,double>; using PIL = pair<int,LL>;
using MII = map<int,int>; using MLL = map<LL,LL>;
using SI = set<int>; using SL = set<LL>;
using MSI = multiset<int>; using MSL = multiset<LL>;
template<class T> using MAXPQ = priority_queue<T>;
template<class T> using MINPQ = priority_queue< T, vector<T>, greater<T> >;

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
#define PI  3.14159265358979323846

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define EACH(e, v) for(auto &e : v)
#define RITR(it, v) for(auto it = (v).rbegin(); it != (v).rend(); ++it)
#define ALL(v) v.begin(),v.end()

vector<ll> x8={1,1,1,0,0,-1,-1,-1},y8={1,0,-1,1,-1,1,0,-1};
int dx4[4]={1,-1,0,0}, dy4[4]={0,0,1,-1};

/*
memo
-uf,RMQ(segtree),BIT,BIT2,SegTree,SegTreeLazy
-isprime,Eratosthenes,gcdlcm,factorize,divisors,modpow,moddiv
nCr(+modnCr,inverse,extend_euclid.powmod),tobaseB,tobase10
-dijkstra,Floyd,bellmanford,sccd,topological,treediamiter
-compress1,compress2,rotate90

-co,ci,fo1,fo2,fo3,fo4
-bitsearch,binaryserach
-bfs
-SegTreedec,SegTreeLazydec
*/



int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(0);
    ll N,M; cin >> N >> M;
    VL u(M),v(M);
    for(ll i = 0; i < M; i++){
        cin >> u[i] >> v[i];
        u[i]--,v[i]--;
    }

    set<ll> iwi;
    ll K; cin >> K;
    for(ll i = 0; i < K; i++){
        ll a; cin >> a;
        iwi.insert(--a);
    }

    vector<PLL> G[N][5];
    for(ll i = 0; i < M; i++){
        if(iwi.count(v[i])){
            for(ll j = 0; j+1 < 5; j++){
                G[u[i]][j].push_back({v[i],j+1});
            }
        }
        else{
            for(ll j = 0; j < 5; j++){
                G[u[i]][j].push_back({v[i],0});
            }
        }

        if(iwi.count(u[i])){
            for(ll j = 0; j+1 < 5; j++){
                G[v[i]][j].push_back({u[i],j+1});
            }
        }
        else{
            for(ll j = 0; j < 5; j++){
                G[v[i]][j].push_back({u[i],0});
            }
        }
    }

    VVL d(N,VL(5,INF));
    d[0][0] = 0;
    queue<PLL> q;
    q.push({0,0});
    while(q.size()){
        auto [pos,con] = q.front(); q.pop();
        for(auto [next,ncon] : G[pos][con]){
            if(d[next][ncon]!=INF) continue;
            d[next][ncon] = d[pos][con]+1;
            q.push({next,ncon});
        }
    }

    ll ans = INF;
    cout << (d[N-1][0]==INF? -1:d[N-1][0]) << '\n';

}