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