#include <cstring>
#include <iostream>
#include <vector>

using namespace std;

class Graph {
public:
    struct Edge {
        int target_vertex = -1;
        int next_edge = -1;
    };

    vector<int> head_edges;
    vector<Edge> edges;

    explicit Graph(int vertices_amount = 0, int edges_amount = 0) : head_edges(vertices_amount, -1) {
        edges.reserve(edges_amount);
    }

    void init(int vertices_amount, int edges_amount) {
        head_edges.resize(vertices_amount, -1);
        edges.reserve(edges_amount);
    }

    void add_edge(int source_vertex, int target_vertex) {
        edges.push_back({target_vertex, head_edges[source_vertex]});
        head_edges[source_vertex] = static_cast<int>(edges.size()) - 1;
    }
};

constexpr int MAX_V = 1e3 + 5;

int cows_amount, vertices_amount, edges_amount, ans;
vector<int> cows_locations;
Graph graph;

bool vis[MAX_V];
int vertices_accessibility[MAX_V];

void dfs(int start_vertex, int current_vertex) {
    if (vis[current_vertex]) { return; }
    vis[current_vertex] = true;
    vertices_accessibility[current_vertex]++;
    for (int edge = graph.head_edges[current_vertex]; edge != -1; edge = graph.edges[edge].next_edge) {
        int next_vertex = graph.edges[edge].target_vertex;
        dfs(start_vertex, next_vertex);
    }
}

void dfs(int start_vertex) {
    memset(vis, false, sizeof(vis));
    dfs(start_vertex, start_vertex);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> cows_amount >> vertices_amount >> edges_amount;
    cows_locations.resize(cows_amount);
    graph.init(vertices_amount, edges_amount);
    for (int i = 0; i < cows_amount; i++) {
        cin >> cows_locations[i], cows_locations[i]--;
    }
    for (int i = 0; i < edges_amount; i++) {
        int source_vertex, target_vertex;
        cin >> source_vertex >> target_vertex, source_vertex--, target_vertex--;
        graph.add_edge(source_vertex, target_vertex);
    }

    for (const int cow : cows_locations) {
        dfs(cow);
    }
    for (int i = 0; i < vertices_amount; i++) {
        if (vertices_accessibility[i] == cows_amount) {
            ans++;
        }
    }
    cout << ans << endl;

    return 0;
}