/* -*- coding: utf-8 -*-
 *
 * 2289.cc:  No.2289 順列ソート - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 100;

/* typedef */

/* global variables */

int ps[MAX_N], qs[MAX_N];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  for (int i = 0; i < n; i++) {
    scanf("%d", ps + i), ps[i]--;
    qs[ps[i]] = i;
  }

  int cnt = 0;
  for (int i = 0; i < n; i++)
    if (ps[i] != i) {
      int j = qs[i];
      swap(qs[ps[i]], qs[ps[j]]);
      swap(ps[i], ps[j]);
      cnt++;
    }

  printf("%d\n", cnt);
  return 0;
}