#include <bits/stdc++.h>
using namespace std;
inline long long read() {
  char c = getchar();
  long long x = 0;
  bool f = 0;
  for (; !isdigit(c); c = getchar()) f ^= !(c ^ 45);
  for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
  if (f) x = -x;
  return x;
}
long long n, a[500005], resl, resr, odd;
long long b[500005], sum[500005];
long long check(long long n, long long mid) {
  long long p = 1;
  a[n] = -1;
  for (register long long i = (1); i <= (n); ++i) {
    b[i] = (p == i && a[p] < mid) ? (mid) : (a[p++]);
    sum[i] = sum[i - 1] + b[i];
  }
  p = n;
  for (register long long k = (1); k <= (n); ++k) {
    while (p > k && b[p] < k) --p;
    long long vl = sum[k];
    long long vr = k * (k - 1) + sum[n] - sum[max(p, k)] + k * (max(p, k) - k);
    if (vl > vr) {
      if (b[k] > mid)
        return -1;
      else
        return 1;
    }
  }
  return 0;
}
signed main() {
  n = read();
  for (register long long i = (1); i <= (n); ++i)
    a[i] = read(), odd ^= (a[i] & 1);
  sort(a + 1, a + n + 1, greater<long long>());
  long long l = 0, r = (n - odd) >> 1;
  resl = 0, resr = -1;
  while (l <= r) {
    long long mid = l + r >> 1;
    if (check(n + 1, mid * 2 + odd) >= 0)
      resl = mid, r = mid - 1;
    else
      l = mid + 1;
  }
  l = 0, r = (n - odd) >> 1;
  while (l <= r) {
    long long mid = l + r >> 1;
    if (check(n + 1, mid * 2 + odd) <= 0)
      resr = mid, l = mid + 1;
    else
      r = mid - 1;
  }
  if (resl > resr)
    puts("-1");
  else {
    for (register long long i = (resl); i <= (resr); ++i)
      cout << i * 2 + odd << ' ';
  }
  return 0;
}
