#include <bits/stdc++.h>
using namespace std;
int a[200005];
int b[200005];
int n;
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    b[i] = a[i] - (n + 1 - i);
  }
  sort(b + 1, b + n + 1);
  for (int i = 1; i <= n; i++) {
    a[i] = b[i] + (n + 1 - i);
  }
  for (int i = 1; i < n; i++) {
    if (a[i] > a[i + 1]) {
      cout << ":(";
      return 0;
    }
  }
  for (int i = 1; i <= n; i++) {
    cout << a[i] << " ";
  }
  return 0;
}
