#include <bits/stdc++.h>
using namespace std;
long long ice_queue[200001];
int main(void) {
  int n;
  while (cin >> n) {
    for (int i = 0; i < n; i++) {
      cin >> ice_queue[i];
      ice_queue[i] += i;
    }
    sort(ice_queue, ice_queue + n);
    bool answer = 1;
    for (int i = 0; i < n - 1; i++)
      if (ice_queue[i] == ice_queue[i + 1]) answer = 0;
    if (answer)
      for (int i = 0; i < n; i++) cout << ice_queue[i] - i << " ";
    else
      cout << ":(";
    cout << endl;
  }
  return 0;
}
