/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int a[]=new int[n+1];
		for(int i=1;i<=n;i++) a[i]=sc.nextInt();
		Map<Integer,Integer>mp=new HashMap<>();
		int i=1;
		int count=0;
		while(i<=n){
			int RHS=a[a[a[i]]];
			count=count+mp.getOrDefault(RHS,0);
			mp.put(RHS,mp.getOrDefault(RHS,0)+1);
			i++;
		}
		System.out.println(count);
	}
}