import java.util.ArrayList;
import java.util.Scanner;

public class _1617 {
    public static void main(String[] args) throws Exception {
        Scanner s = new Scanner(System.in);
        ArrayList<Integer> list = new ArrayList<Integer>();
        int n, i, count1 = 0, count2 = 0;

        n = s.nextInt();
        int[] res = new int[n];
        for (i = 0; i < n; i++) {
            res[i] = s.nextInt();
            list.add(res[i]);
        }

        int e = 0;
        for (i = 0; i < list.size(); i++) {
            if (list.get(e).equals(res[i])) {
                count1++;
                if (count1 == 4) {
                    count2++;
                }
            }
        }
        System.out.println(count2);
    }
}