#include <bits/stdc++.h>
using namespace std;
int n, *a;
int main() {
  ios_base::sync_with_stdio(0);
  cin >> n;
  a = new int[n];
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    a[i] += i;
  }
  sort(a, a + n);
  for (int i = 0; i < n; ++i) {
    a[i] -= i;
    if (a[i] < 0 || (i && a[i] < a[i - 1])) {
      delete[] a;
      cout << ":(";
      return 0;
    }
  }
  for (int i = 0; i < n; ++i) cout << a[i] << ' ';
  delete[] a;
  return 0;
}
