#include <bits/stdc++.h>
using namespace std;
int n, a[200009];
int main() {
  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;
  bool ok = 1;
  for (int i = 1; i < n; i++) {
    if (a[i - 1] > a[i]) {
      ok = 0;
      break;
    }
  }
  if (!ok)
    puts(":(");
  else {
    for (int i = 0; i < n; i++) printf("%d ", a[i]);
  }
  return 0;
}
