#include<bits/stdc++.h>

using namespace std;

#define lowbit(x) ((x)&(-x))

typedef long long LL;

typedef pair<int,int> pii;

const int maxn = 2e5+;

vector<int> G[maxn];

int d1[maxn], d2[maxn];

bool ks[maxn];

void bfs(int *dist, int s) {

    dist[s] = ;

    queue<int> q;

    q.push(s);

    while(!q.empty()) {

        int u = q.front();

        q.pop();

        for(auto v : G[u]) {

            if(dist[v] == -) {

                q.push(v);

                dist[v] = dist[u] + ;

            }

        }

    }

}

void run_case() {

    int n, m, k;

    cin >> n >> m >> k;

    memset(d1, -, sizeof(d1)), memset(d2, -, sizeof(d2));

    for(int i = ; i < k; ++i) {

        int t; cin >> t;

        ks[t] = true;

    }

    for(int i = ; i < m; ++i) {

        int u, v;

        cin >> u >> v;

        G[u].push_back(v);

        G[v].push_back(u);

    }

    bfs(d1, );

    bfs(d2, n);

    vector<pii> v;

    for(int i = ; i <= n; ++i) if(ks[i]) v.emplace_back(d1[i], d2[i]);

    sort(v.begin(), v.end(), [&](const pii &a, const pii &b) {

        return a.first - a.second < b.first - b.second;

    });

    int ans = , mx = v[].first;

    for(int i = ; i < v.size(); ++i) {

        ans = max(ans, mx++v[i].second);

        mx = max(mx, v[i].first);

    }

    cout << min(ans, d1[n]);

}

int main() {

    ios::sync_with_stdio(false), cin.tie();

    //cout.setf(ios_base::showpoint);cout.precision(10);

    //int t; cin >> t;

    //while(t--)

    run_case();

    cout.flush();

    return ;

}