#include <iostream>
#include <vector>

int main(int argc, char const *argv[])
{
  std::ios_base::sync_with_stdio(false);

  int n;
  while (std::cin >> n)
  {
    std::vector<int> vec(n + 1), index(n + 1);
    for (int i = 1; i <= n; ++i)
    {
      std::cin >> vec[i];
      index[vec[i]] = i;
    }

    int eps = 0;
    for (int i = 1; i <= n; ++i)
    {
      if (i != vec[i])
      {
        ++eps;
        vec[index[i]] = vec[i];
        index[vec[i]] = index[i];
      }
    }

    std::cout << eps << '\n';
  }

  return 0;
}