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