static void Main()
{
var(n, m, k) = Read3();
var a = Read();
var es = Array.ConvertAll(new bool[m], _ => (Edge)Read());
var map = new UnweightedMap(n + 1, es, false);
var set = a.ToHashSet();
var already = es.Any(e => set.Contains(e.From) && set.Contains(e.To));
if (already)
{
var r1 = map.Bfs(1, n);
Console.WriteLine(r1[n]);
}
else
{
var r1 = map.Bfs(1, -1);
var rn = map.Bfs(n, -1);
long M = 0, M1 = -1;
var vs = a.Select(i => (i, d: r1[i] - rn[i])).OrderBy(v => v.d);
foreach (var(i, _) in vs)
{
if (M1 != -1)
{
M = Math.Max(M, M1 + rn[i]);
}
M1 = Math.Max(M1, r1[i]);
}
M++;
Console.WriteLine(Math.Min(r1[n], M));
}
}
static object Solve()
{
var(n, m) = Read2();
var es = GraphConsole.ReadEdges(m);
var k = int.Parse(Console.ReadLine());
var p = Read();
var map = new UnweightedMap(n + 1, es, true);
var map_r = new UnweightedMap(n + 1, Array.ConvertAll(es, e => e.Reverse()), true);
var r = map_r.Bfs(p.Last());
var(min, max) = (0, 0);
for (int i = 0; i < k - 1; i++)
{
if (r[p[i]] <= r[p[i + 1]])
{
min++;
max++;
}
else
{
if (map[p[i]].Count(v => r[v] < r[p[i]]) > 1)
{
max++;
}
}
}
return($"{min} {max}");
}