#include <bits/stdc++.h>
using namespace std;
int main() {
  int n = 0;
  cin >> n;
  vector<int> data(n);
  for (int i = 0; i < n; ++i) {
    int tmp = 0;
    cin >> tmp;
    data[i] = tmp - n + i + 1;
  }
  sort(data.begin(), data.end());
  cout << endl;
  for (int i = 0; i < n - 1; ++i) {
    if (data[i] > data[i + 1] - 1) {
      cout << ":(";
      return 0;
    }
  }
  for (int i = 0; i < n; ++i) {
    cout << (data[i] + n - i - 1) << ' ';
  }
  return 0;
}
