import java.util.Scanner;

public class Monsters {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        while (sc.hasNextInt()) {
            int cells = sc.nextInt();
            int[] chambers = new int[cells];

            for (int i = 0; i < cells; i++) {
                int monster = sc.nextInt() - 1;
                chambers[i] = monster;
            }

            int swaps = 0;

            for (int i = 0; i < cells; i++) {
                while (chambers[i] != i) {
                    int temp = chambers[chambers[i]];
                    chambers[chambers[i]] = chambers[i];
                    chambers[i] = temp;
                    swaps++;
                }
            }
            System.out.println(swaps);
        }
    }
}