#include <bits/stdc++.h>
using namespace std;
int main() {
  int num;
  int dollar;
  vector<int> money;
  vector<int> comper;
  scanf("%d", &num);
  int i = 0;
  while (i < num) {
    scanf("%d", &dollar);
    money.push_back(dollar + i);
    i++;
  }
  sort(money.begin(), money.end());
  int j = 0;
  while (j < num) {
    money[j] -= j;
    j++;
  }
  comper = money;
  sort(comper.begin(), comper.end());
  if (comper != money)
    printf(":(");
  else {
    i = 0;
    while (i < num) {
      printf("%d ", money[i]);
      i++;
    }
  }
}
