#include <bits/stdc++.h>
using namespace std;
int n, a[200005];
int main() {
  scanf("%d", &n);
  for (register int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    a[i] += i;
  }
  sort(a + 1, a + n + 1);
  for (register int i = 1; i <= n; i++) a[i] -= i;
  for (register int i = 2; i <= n; i++)
    if (a[i - 1] > a[i]) {
      puts(":(");
      return 0;
    }
  for (register int i = 1; i <= n; i++) printf("%d ", a[i]);
  return 0;
}
