#include <bits/stdc++.h>
using namespace std;
using ll=long long;

int main() {
	// your code goes here
	ll n;
	cin>>n;
	vector<ll>arr(n+1);
	for(ll i=1;i<=n;i++) cin>>arr[i];
	unordered_map<ll,ll>mp;
	ll ans=0;
	
	for(ll j=1;j<=n;j++){
		ans+=mp[arr[arr[arr[j]]]];
		mp[arr[arr[arr[j]]]]++;
		
	}
	cout<<ans<<endl;
	return 0;
}