#include <bits/stdc++.h>
using namespace std;
const int maxn = 500000;
int a[maxn];
int main() {
  ios_base::sync_with_stdio(0);
  int n, i;
  cin >> n;
  for (i = 0; i < n; ++i) {
    cin >> a[i];
    a[i] += i;
  }
  sort(a, a + n);
  for (i = 0; i < n; ++i) {
    if (i < n - 1 && a[i] == a[i + 1]) {
      cout << ":(" << endl;
      return 0;
    }
    a[i] -= i;
  }
  for (i = 0; i < n; ++i) cout << a[i] << ' ';
  cout << endl;
  return 0;
}
