#include <iostream>

int main(){
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);
	std::cout.tie(0);
	int n;
	std::cin >> n;
	int vec[100000];
	for (int i = 1;i <= n;i++){
		std::cin >> vec[i];
	}
	int ans = 0;
	for (int i = 1;i <= n;i++){
		while (vec[i] != i){
			int temp = vec[i];
			vec[i] = i;
			vec[temp] = temp;
			ans++;
		}
	}
	std::cout << ans;
	return 0;
}