#include <bits/stdc++.h>
using namespace std;
int a[200010], b[200010];
int main() {
  int n, t, q;
  while (~scanf("%d", &n)) {
    t = 1;
    if (n == 1) {
      scanf("%d", &q);
      printf("%d\n", q);
      continue;
    } else {
      for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
        b[i] = a[i] + i;
      }
      sort(b + 1, b + n + 1);
      for (int i = 1; i < n; i++)
        if (b[i] == b[i + 1]) t = 0;
      if (t) {
        for (int i = 1; i < n; i++) printf("%d ", b[i] - i);
        printf("%d\n", b[n] - n);
      } else
        printf(":(\n");
    }
  }
}
