#include <bits/stdc++.h>
using namespace std;
const int maxn = 200010;
pair<int, int> a[maxn];
int N, x[maxn], i;
int main() {
  scanf("%d", &N);
  for (i = 1; i <= N; i++) {
    scanf("%d", &x[i]);
    a[i] = {x[i] + i, i};
  }
  sort(a + 1, a + N + 1);
  for (i = 1; i < N; i++)
    if (a[i].first == a[i + 1].first) return puts(":("), 0;
  for (i = 1; i <= N; i++) printf("%d ", x[a[i].second] - (i - a[i].second));
  return 0;
}
