#include <bits/stdc++.h>
using namespace std;
vector<int> t;
vector<int> res;
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int a;
    cin >> a;
    int pos = n - i;
    t.push_back(a - pos + 1);
  }
  sort(t.begin(), t.end());
  int prev_val = 1 << 30;
  int place = 0;
  for (int i = t.size() - 1; i >= 0; i--) {
    int val = t[i] + place;
    if (val > prev_val) {
      cout << ":(\n";
      return 0;
    }
    res.push_back(val);
    prev_val = val;
    place++;
  }
  for (int i = res.size() - 1; i >= 0; i--) {
    cout << res[i] << " ";
  }
  cout << endl;
}
