#include <bits/stdc++.h>
using namespace std;
int n, a[200015], i, n1;
bool doit() {
  n1 = n - 1;
  for (i = 0; n1; ++i) {
    if (a[i] == a[i + 1]) {
      printf(":(");
      return 0;
    }
    a[i] += n1;
    --n1;
  }
  for (i = 0; i < n; ++i) printf("%d ", a[i]);
}
int main() {
  scanf("%d", &n);
  i = n;
  while (i) {
    --i;
    scanf("%d", a + i);
    a[i] -= i;
  }
  sort(a, a + n);
  doit();
}
