#include <fstream>
#include <iostream>
#include <vector>
#include <queue>

using namespace std;

const int N = 1e5 + 2, oo = 2e9;

vector <int> L[N];
vector <int> from, dist;
queue <int> q;
int n;

void Read()
{
	ifstream fin("reinvent.in");
	int m, x;
	fin >> n >> m >> x;
	from = vector<int>(n + 1, 0);
	dist = vector<int>(n + 1, oo);
	while (m--)
	{
		int y, z;
		fin >> y >> z;
		L[y].push_back(z);
		L[z].push_back(y);
	}
	while (x--)
	{
		int vertex;
		fin >> vertex;
		dist[vertex] = 0;
		from[vertex] = vertex;
		q.push(vertex);
	}
}

void Solve()
{
	int sol = oo;
	while (!q.empty())
	{
		int v = q.front();
		q.pop();
		for (auto next : L[v])
		{
			if (from[next] && from[v] && from[next] != from[v])
				sol = min(sol, dist[next] + dist[v] + 1);
			if (dist[next] > 1 + dist[v])
			{
				dist[next] = 1 + dist[v];
				from[next] = from[v];
				q.push(next);
			}
		}
	}
	ofstream fout("reinvent.out");
	fout << sol << "\n";
}

int main ()
{
	Read();
	Solve();
	return 0;
}