#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<int> a(n);
  vector<pair<int, int>> b;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    b.push_back({a[i] + i, i});
  }
  sort((b).begin(), (b).end());
  vector<int> c;
  for (int i = 0; i < n; i++) c.push_back(a[b[i].second] - i + b[i].second);
  if (is_sorted((c).begin(), (c).end())) {
    for (auto i : c) cout << i << " ";
  } else {
    cout << ":(";
  }
  return 0;
}
