#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  vector<pair<int, int> > df;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    df.push_back(make_pair(x + (i + 1), i + 1));
  }
  sort(df.begin(), df.end());
  int mini = 2 * 1e9;
  vector<int> ans;
  for (int i = n - 1; i >= 0; i--) {
    int x = df[i].first - (i + 1);
    if (x < 0) {
      cout << ":(\n";
      return 0;
    }
    if (x > mini) {
      cout << ":(\n";
      return 0;
    }
    mini = min(mini, x);
    ans.push_back(x);
  }
  reverse(ans.begin(), ans.end());
  for (int i = 0; i < n; i++) cout << ans[i] << " ";
  cout << '\n';
}
