//Nguyen Huu Hoang Minh
#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 200005
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "test"
#define int long long

using namespace std;

typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;

int n, m, k;
vector<int> a[N];
int d[N];
int g[N];
int qu[N];

void readfile()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    if (fopen(Task".inp","r"))
    {
        freopen(Task".inp","r",stdin);
        //freopen(Task".out","w",stdout);
    }
    cin >> n >> m >> k;
    for(int i=1; i<=k; i++) cin >> qu[i];
    for(int i=1; i<=m; i++)
    {
        int u, v;
        cin >> u >> v;
        a[u].pb(v);
        a[v].pb(u);
    }
}

void dijkstra()
{
    priority_queue<ii, vii, greater<ii>> q;
    q.push(ii(0,1));
    for(int i=1; i<=n; i++) d[i] = inf, g[i] = inf;
    d[1] = 0;
    g[n] = 0;
    while (q.size())
    {
        int u = q.top().se;
        int du = q.top().fi;
        q.pop();
        if (du != d[u]) continue;
        for(auto v : a[u])
        {
            if (d[v] > d[u] + 1)
            {
                d[v] = d[u] + 1;
                q.push(ii(d[v],v));
            }
        }
    }
    q.push(ii(0,n));
    while (q.size())
    {
        int u = q.top().se;
        int du = q.top().fi;
        q.pop();
        if (g[u] != du) continue;
        for(auto v : a[u])
        {
            if (g[v] > g[u] + 1)
            {
                g[v] = g[u] + 1;
                q.push(ii(g[v],v));
            }
        }
    }
}

void proc()
{
    dijkstra();
    int res = d[n];
    int ans = minf;
    int best = 0;
    vector<ii> dat(k+1);
    for(int i=1; i<=k; i++)
    {
        int u = qu[i];
        dat.pb(ii(d[u]-g[u],u));
    }
    sort(dat.begin(),dat.end());
    for(auto i : dat)
    {
        int x = i.se;
        best = max(best, ans+g[x]);
        ans = max(ans, d[x]);
    }
    cout << min(res,best+1);
}

signed main()
{
    readfile();
    proc();
    return 0;
}