#include <iostream>

using namespace std;

int main(void) {
	
	while(true) {
	
		int delka;
		cin >> delka;
		if(cin.eof()) break;
		
		int pole[delka];
		for(int i = 0; i < delka; i++) {
			cin >> pole[i];
		}
	
		int counter = 0;
		for(int i = 1; i <= delka; i++) {
			while(pole[i - 1] != i) {
				int tmp = pole[pole[i - 1] - 1];
				pole[pole[i - 1] - 1] = pole[i - 1];
				pole[i - 1] = tmp;
				counter++;
			}
		}
		cout << counter << endl;
	
	}
	
	
	
	
}