#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.sync_with_stdio(0);
  cin.tie(0);
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++) cin >> A[i];
  reverse(begin(A), end(A));
  for (int i = 0; i < N; i++) A[i] -= i;
  sort(begin(A), end(A));
  for (int i = 1; i < N; i++)
    if (A[i] == A[i - 1]) {
      cout << ":(\n";
      return 0;
    }
  reverse(begin(A), end(A));
  for (int i = 0; i < N; i++) A[i] += i;
  reverse(begin(A), end(A));
  for (int i = 0; i < N; i++) cout << A[i] << ((i == N - 1) ? "\n" : " ");
  return 0;
}
