#include <bits/stdc++.h>
using namespace std;
int n, k, k1, k2, st, den;
vector<pair<int, int> > a;
bool cmp(pair<int, int> a, pair<int, int> b) {
  return a.first - (n - a.second - 1) < b.first - (n - b.second - 1);
}
int main() {
  cin >> n;
  a.resize(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i].first;
    a[i].second = i;
  }
  sort(a.begin(), a.end(), cmp);
  for (int i = 0; i < n; i++) {
    a[i].first += a[i].second - i;
    if (i > 0 && a[i].first < a[i - 1].first) {
      cout << ":(";
      return 0;
    }
  }
  for (int i = 0; i < n; i++) cout << a[i].first << " ";
  return 0;
}
