#include <bits/stdc++.h>
using namespace std;
const long long N = 2e5 + 5;
long long n, k, sum, l, x, m, i, a, b[N];
vector<long long> ans;
int main() {
  cin >> n;
  if (n == 1) {
    cin >> a;
    cout << a;
    return 0;
  }
  for (long long i = 0; i < n; i++) {
    cin >> a;
    b[i] = a + i;
  }
  sort(b, b + n);
  for (long long i = 0; i < n; i++) {
    ans.push_back(b[i] - i);
    if (b[i] == b[i + 1]) return cout << ":(" << endl, 0;
  }
  for (long long i = 0; i < n; i++) {
    cout << ans[i] << " ";
  }
}
