#include <bits/stdc++.h>
using namespace std;
int sum[200000 + 5];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    scanf("%d", sum + i);
    sum[i] += i;
  }
  sort(sum, sum + n);
  for (int i = 1; i < n; ++i) {
    if (sum[i] == sum[i - 1]) {
      printf(":(\n");
      return 0;
    }
  }
  for (int i = 0; i < n; ++i) {
    printf("%d ", sum[i] - i);
  }
  printf("\n");
}
