#include <bits/stdc++.h>
using namespace std;
int v[200001], n;
bool check() {
  int maxx = v[0];
  for (int i = 1; i < n; ++i) {
    if (v[i] < maxx) return 0;
    maxx = max(v[i], maxx);
  }
  return 1;
}
void output(bool r) {
  if (r == 0)
    cout << ":(";
  else
    for (int i = 0; i < n; ++i) cout << v[i] << " ";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0), cout.tie(0);
  cin >> n;
  int i;
  for (i = 0; i < n; ++i) cin >> v[i], v[i] += i;
  sort(v, v + n);
  for (i = 0; i < n; ++i) v[i] -= i;
  output(check());
  return 0;
}
