#include <bits/stdc++.h>
using namespace std;
int a[200010];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    a[i] += i;
  }
  sort(a, a + n);
  for (int i = 0; i < n; i++) a[i] -= i;
  for (int i = 0; i < n - 1; i++)
    if (a[i] > a[i + 1]) {
      printf(":(\n");
      return 0;
    }
  for (int i = 0; i < n; i++) printf("%d ", a[i]);
  printf("\n");
  return 0;
}
