#include <bits/stdc++.h>
using namespace std;
int n, a[200001];
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d", a + i), a[i] += i;
  sort(a + 1, a + n + 1);
  for (int i = 1; i <= n; i++) {
    a[i] -= i;
    if (a[i] < a[i - 1]) printf(":("), exit(0);
  }
  for (int i = 1; i <= n; i++) printf("%d ", a[i]);
}
