#include <iostream>
#include <string.h>
using namespace std;
int k, n, m;
int xx, yy;
typedef struct {
	int xq[1001][1001];
	int vis[1001];
}MuChang;
int sum[1001];
int Niu[1001];
int ans;
MuChang z;
void dfs(int x) {
	for (int i = 1; i <= n; i++) {
		if (z.vis[i] == 0 && z.xq[x][i] == 1) {
			z.vis[i] = 1;
			sum[i]++;
			dfs(i);
		}
	}
}
int main() {
	cin >> k >> n >> m;   //输入奶牛的个数    牧场的个数   牧场之间多少条道路
	for (int i = 1; i <= k; i++) {
		cin >> Niu[i];
		sum[Niu[i]]++;
	}
	for (int i = 1; i <= m; i++) {
		cin >> xx >> yy;
		z.xq[xx][yy] = 1;
	}
	for (int i = 1; i <= k; i++) {
		memset(z.vis, 0, sizeof(z.vis));
		dfs(Niu[i]);
	}
	for (int i = 1; i <= n; i++) {
		if (sum[i] == k) {
			ans++;
		}
	}
	cout << ans << endl;
	return 0;
}