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

#define rep(i, n) for (int i = 0; i < (int)n; i++)

int main() {
  int N;
  cin >> N;
  map<int, vector<int>> mp;
  rep(i, N) {
    int Ai;
    cin >> Ai;
    mp[Ai].push_back(i);
  }
  int l = -1, r = N;
  for (auto it = mp.begin(); it != mp.end(); it++) {
    if ((it->second).size() > 2) {
      l = N, r = -1;
    }
    if ((it->second).size() == 2) {
      l = max((it->second)[0], l);
      r = min((it->second)[1], r);
    }
  }
  if (l > r) {
    cout << 0 << endl;
    cout << endl;
  } else if (l < 0) {
    cout << N-1 << endl;
    rep(i, N-1)
      cout << i+1 << " ";
    cout << endl;
  } else {
    cout << r - l << endl;
    for (int i = l; i < r; i++)
      cout << i+1 << " ";
    cout << endl;
  }
  return 0;
}