#include using namespace std; using ll=long long; const ll ILL=2167167167167167167; const int INF=2100000000; #define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++) #define all(p) p.begin(),p.end() template using _pq = priority_queue, greater>; template int LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template int UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,T b){if(b bool chmax(T &a,T b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;} template void vec_out(vector &p,int ty=0){ if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'< T vec_min(vector &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;} template T vec_max(vector &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;} template T vec_sum(vector &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;} int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;} template T square(T a){return a * a;} void solve(); // POP'N ROLL MUSIC / TOMOO int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t = 1; // cin >> t; rep(i, 0, t) solve(); } void solve(){ int N, M; cin >> N >> M; vector> G(N); rep(i, 0, M){ int a, b; cin >> a >> b; a--, b--; G[a].push_back(b); G[b].push_back(a); } int K; cin >> K; vector A(N); rep(i, 0, K){ int a; cin >> a; A[a - 1] = 1; } int X = 5; vector dp(X, vector(N, -1)); vector> order = {{0, 0}}; dp[0][0] = 0; rep(rp, 0, order.size()){ auto [k, ind] = order[rp]; for (auto nx : G[ind]){ int a = k; if (A[nx]) a++; else a = 0; if (a == X) continue; if (dp[a][nx] == -1){ dp[a][nx] = dp[k][ind] + 1; order.push_back({a, nx}); } } } int ans = INF; rep(i, 0, X) if (dp[i][N - 1] != -1) chmin(ans, dp[i][N - 1]); if (ans == INF) ans = -1; cout << ans << "\n"; }