#include <bits/stdc++.h>
using namespace std;
const long long hell = 1000000007;
const long long INF = 1000000000;
void solve() {
  long long n;
  cin >> n;
  map<long long, long long> mp;
  long long a[n];
  long long s = 0;
  for (long long i = 0; i < n; i++) {
    cin >> a[i];
    s += a[i];
    mp[a[i]]++;
  }
  vector<long long> ans;
  for (long long i = 0; i < n; i++) {
    long long S = s - a[i];
    if (S % 2) continue;
    mp[a[i]]--;
    S = S / 2;
    if (mp[S]) ans.push_back(i);
    mp[a[i]]++;
  }
  cout << ans.size() << endl;
  for (long long j : ans) cout << j + 1 << " ";
  cout << endl;
}
int32_t main() {
  long long t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
