#include <bits/stdc++.h>
using namespace std;
int a[2 * 100010];
bool solve(int n) {
  sort(a, a + n);
  for (int i = 0; i < n; i++) a[i] -= i;
  for (int i = 1; i < n; i++)
    if (a[i] < a[i - 1]) return false;
  return true;
}
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    a[i] += i;
  }
  if (solve(n)) {
    for (int i = 0; i < n - 1; i++) printf("%d ", a[i]);
    printf("%d\n", a[n - 1]);
  } else
    printf(":(\n");
}
