#include<iostream>

using namespace std;
int way[10000][2];
int rea[1000];
bool vis[1000];
int k, n, m;
void work(int a)
{
	int j;
	for(j = 0; j < n; j ++)
		if( a == way[j][0] && vis[way[j][1]] == false)
		{
            rea[way[j][1]] ++;
			vis[way[j][1]] = true;
		    work(way[j][1]);
		}
}
int main()
{
	while( 3 == scanf("%d %d %d", &k, &n, &m) )
	{
		int i;
		int* cow = new int [n];
		for(i = 0; i < k; i ++ )
			scanf("%d", &cow[i]);
		for(i = 0; i < m; i ++ )
			scanf("%d %d", &way[i][0], &way[i][1] );
		memset(rea, 0, sizeof(rea) );
		for(i = 0; i < k; i ++)
		{
			memset(vis,false, sizeof(vis));
			vis[cow[i]] = true;
			rea[cow[i]] ++;
			work(cow[i]);
		}
		int cnt = 0;
       for(i = 1; i <= n; i ++)
	   if(rea[i] == k)
		   cnt ++;
	   printf("%d\n", cnt);
	}
	return 0;
}