#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[200001];
  int n, i, check;
  while (scanf("%d", &n) != EOF) {
    check = 1;
    for (i = 1; i <= n; i++) {
      scanf("%d", &a[i]);
      a[i] = a[i] + i;
    }
    sort(a, a + i);
    a[1] = a[1] - 1;
    for (i = 2; i <= n; i++) {
      a[i] = a[i] - i;
      if (a[i] < a[i - 1]) {
        printf(":(\n");
        check = 0;
        break;
      }
    }
    if (check) {
      for (i = 1; i <= n; i++) printf("%d ", a[i]);
      printf("\n");
    }
  }
  return 0;
}
