#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

void solve() {
  ll n, cnt = 0;
  cin >> n;
  map<ll, ll> mpl, mpr;
  vector<ll> a(n);
  rep(i, n) {
    cin >> a[i];
    if (++mpr[a[i]] == 2)
      cnt++;
  }
  vector<ll> ans;
  rep(i, n - 1) {
    if (--mpr[a[i]] == 1)
      cnt--;
    if (++mpl[a[i]] == 2)
      break;
    if (cnt == 0)
      ans.push_back(i + 1);
  }
  cout << ans.size() << '\n';
  rep(i, ans.size()) cout << (i ? " " : "") << ans[i];
  cout << '\n';
}

int main() {
  std::cin.tie(nullptr);
  std::ios_base::sync_with_stdio(false);
  int T = 1;
  for (int t = 0; t < T; t++) {
    solve();
  }
  return 0;
}