import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;

/**
 *
 * @author muran4
 */
public class Monsters {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws IOException {
        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
        
        String line;
        String[] arr;
        int[] serie;
        int[] position;
        int num;
        while((line = input.readLine())!=null){
            num = Integer.parseInt(line);
            line = input.readLine();
            //arr = line.split(" ");
            Scanner in = new Scanner(line);
            serie = new int[num];
            position = new int[num+1];
            for (int i = 0; i < num; i++) {
                serie[i] = in.nextInt();
                position[serie[i]] = i;
            }
            
            int pos;
            int temp;
            int pocet = 0;
            for (int i = 0; i < num; i++) {
                if(serie[i]!=i+1){
                    temp = serie[i];
                    serie[i] = i+1;
                    position[temp] = position[serie[i]];
                    serie[position[serie[i]]] = temp;
                    pocet++;
                }
            }
            System.out.println(pocet);
            
            
        }
    }
    
}