/* 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> m=new HashMap<>();
		int count=0;
		for(int i=1;i<=n;i++)
		{
			int rhs=a[a[a[i]]];
			if(m.containsKey(rhs))
			count+=m.get(rhs);
			m.put(rhs,m.getOrDefault(rhs,0)+1);
		}
		System.out.println(count);
	}
}

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NAo0IDIgMSAy

4
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