#include<bits/stdc++.h>
using namespace std;
using ll = long long;

#define dbg(a)  cerr << #a << ": " << a << "\n"

struct DSU {
  vector<int> par, sz;
  DSU(int n): par(n), sz(n,1) {
    iota(par.begin(), par.end(), 0);
  }

  int find(int v) {
    return (par[v] == v)? v: (par[v] = find(par[v]));
  }

  void unite(int u, int v) {
    u = find(u), v = find(v);
    if(u != v){
      if(sz[u] < sz[v]) {
        swap(u, v);
      }
      par[v] = u;
      sz[u] += sz[v];
    }
  }

  int size(int v) {
    return sz[find(v)];
  }

  bool same_set(int u, int v) {
    return find(u) == find(v);
  }
};

void solve() {
  int n;  cin >> n;
  DSU dsu(n);
  for (int i = 0; i < n; ++i) {
    int pi;  cin >> pi;  pi--;
    dsu.unite(i, pi);
  }
  int ans = n;
  for (int i = 0; i < n; ++i) {
    ans -= (dsu.find(i) == i);
  }
  cout << ans << "\n";
}

int main(){
  ios::sync_with_stdio(0), cin.tie(0);

  int tc = 1;
  for (int t = 1; t <= tc; ++t) {
    solve();
  }
}