#include <bits/stdc++.h>
using namespace std;
const int maxn = 200200;
int N, ar[maxn];
int main() {
  scanf("%d", &N);
  for (int i = 1; i <= N; i++) {
    scanf("%d", &ar[i]);
    ar[i] += i;
  }
  sort(ar + 1, ar + 1 + N);
  for (int i = 1; i <= N; i++) ar[i] -= i;
  for (int i = 1; i < N; i++)
    if (ar[i] > ar[i + 1]) {
      puts(":(");
      return 0;
    }
  for (int i = 1; i <= N; i++) printf("%d ", ar[i]);
  return 0;
}
