#include <iostream>
#include <cstdio>
using namespace std;
const int N = 1e4 + 5;

int arr[N];

int main()
{
    int n, res = 0;
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i)
        scanf("%d", &arr[i]);
    for (int i = 1; i <= n; ++i)
    {
        while (arr[i] != i)
        {
            ++res;
            swap(arr[i], arr[arr[i]]);
        }
    }
    printf("%d", res);
    return 0;
}