#include <bits/stdc++.h>
using namespace std;
long long d[1000000];
long long prefix[1000000];
int main() {
  ios::sync_with_stdio(0);
  long long n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> d[i];
    d[i] *= -1;
  }
  sort(d, d + n);
  for (int i = 1; i <= n; i++) prefix[i] = -d[i - 1] + prefix[i - 1];
  long long low = 0, high = 1e9;
  for (long long k = 1; k <= n; k++) {
    long long ik = lower_bound(d, d + n, -k) - d;
    ik = max(ik, k - 1);
    long long sum2 = 1LL * k * (ik - (k - 1)) + prefix[n] - prefix[ik];
    sum2 = 1LL * k * (k - 1) + sum2 - prefix[k];
    if (sum2 < 0) high = -1;
    high = min(high, sum2 + (-d[k - 1]));
    low = max(low, min((-d[k]), k) - sum2);
  }
  vector<int> ans;
  for (int i = low + (low % 2 ^ prefix[n] % 2); i <= high; i += 2)
    ans.push_back(i);
  if (!ans.size())
    cout << -1 << '\n';
  else {
    for (int i : ans) cout << i << ' ';
    cout << '\n';
  }
}
