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

template<class T> istream& operator >> (istream& is, vector<T>& vec) {
	for(T& x : vec) is >> x;
	return is;
}

template<class T> ostream& operator << (ostream& os, const vector<T>& vec) {
	if(vec.empty()) return os;
	os << vec[0];
	for(auto it = vec.begin(); ++it != vec.end(); ) os << ' ' << *it;
	return os;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	vector<int> a(n);
	cin >> a;
	int ans = 0;
	vector<bool> used(n);
	for(int i = 0; i < n; i++){
		if(used[i]) continue;
		ans++;
		int cur = i;
		while(!used[cur]){
			used[cur] = true;
			cur = a[cur] - 1;
		}
	}
	cout << ans << endl;
}