#include <bits/stdc++.h>
using namespace std;
long long a[300000], x[300000];
int main() {
  long long n, i, k;
  cin >> n;
  k = n - 1;
  for (i = 1; i <= n; i++) cin >> a[i], a[i] -= k, k--;
  sort(a + 1, a + 1 + n);
  k = 0;
  for (i = n; i >= 2; i--) {
    if (a[i] == a[i - 1]) {
      cout << ":(";
      return 0;
    }
    x[i] = a[i] + k;
    k++;
  }
  cout << a[1] + k << ' ';
  for (i = 2; i <= n; i++) cout << x[i] << ' ';
  return 0;
}
