#include <cstdlib>
#include <iostream>
#include <vector>

using namespace std;


int main(int argc, char** argv) {

    long l = 0;
    
    while (cin >> l) {
    
        vector<long> monsters;
        
        for (long i = 0 ; i < l ; i++ ) {
            int tmp;
            cin >> tmp;
            monsters.push_back(tmp);
        }

        long cnt = 0;
        for (long i = 0; i < l; i++) {
            while (monsters[i] - 1 != i) {
                swap(monsters[ monsters[i] - 1 ], monsters[i]);
                cnt++;
            }
        }

        cout << cnt << endl;
    
    }
        
    return 0;
}