#include <bits/stdc++.h>
using namespace std;
int a[230000], b[230000];
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    a[i] += i;
  }
  sort(a + 1, a + n + 1);
  b[0] = 0;
  for (int i = 1; i <= n; i++) {
    b[i] = a[i] - i;
    if (b[i] < b[i - 1]) {
      printf(":(\n");
      return 0;
    }
  }
  for (int i = 1; i < n; i++) printf("%d ", b[i]);
  printf("%d\n", b[n]);
  return 0;
}
