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