#include <bits/stdc++.h>
using namespace std;
int n, a[200500];
int main() {
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    a[i] += i;
  }
  sort(a, a + n);
  for (int i = 1; i < n; ++i) {
    if (a[i] == a[i - 1]) {
      cout << ":(\n";
      return 0;
    }
  }
  for (int i = 0; i < n; ++i) {
    cout << a[i] - i << ' ';
  }
  return 0;
}
