#include<iostream>
using namespace std;

const int N = 10010;
int a[N];
int n, res;

int main()
{
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> a[i];

    for (int i = 1; i <= n; i++)
    {
        while(a[i] != i)
        {
            swap(a[i], a[a[i]]);
            res++;
        }
    }

    cout << res << endl;
    return 0;
}