#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;

using i32 = int;
using i64 = long long;
using u64 = unsigned long long;
using i128 = __int128_t;
using f64 = long double;
using p2 = pair<i64, i64>;
using el = tuple<i64, i64, i64>;
using mint = atcoder::modint998244353;

void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  _main();
}

i128 pow(i128 x, i128 n) {
  i64 res = 1;
  i64 t = x;
  while (n > 0) {
    if (n & 1) {
      res = res * t;
    }
    t = t * t;
    n >>= 1;
  }
  return res;
}
i64 pow(i64 x, i64 n, i64 m) {
  i64 res = 1;
  i64 t = x % m;
  while (n > 0) {
    if (n & 1) {
      res = res * t % m;
    }
    t = t * t % m;
    n >>= 1;
  }
  return res;
}

void _main() {
  i64 n;
  cin >> n;
  vector<i64> p(n);
  vector<bool> ok(n, false);
  vector<vector<i64>> g(n);
  for (i64 i = 0; i < n; i++) {
    cin >> p[i];
    p[i]--;
    if (p[i] >= 0) g[p[i]].push_back(i);
  }
  for (i64 i = 0; i < n; i++) {
    if (p[i] < 0) continue;
    for (i64 ni : g[i]) {
      if (g[ni].empty()) {
        ok[p[i]] = true;
      }
    }
  }
  i64 ans = 0;
  for (i64 i = 0; i < n; i++) {
    ans += ok[i];
  }
  cout << ans << "\n";
}