#include <bits/stdc++.h>
using namespace std;
const int N = 200005;
int a[N];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    int x;
    scanf("%d", &x);
    a[i] = x - n + i + 1;
  }
  sort(a, a + n);
  for (int i = 1; i < n; i++)
    if (a[i] == a[i - 1]) return puts(":("), 0;
  for (int i = 0; i < n; i++) printf("%d ", a[i] + n - i - 1);
  putchar('\n');
  return 0;
}
