#include <bits/stdc++.h>
#pragma warning(disable : 4996)
#pragma comment(linker, "/STACK:336777216")
using namespace std;
const long long MOD = 1e9;
const int INF = 0x7fffffff;
const long long LLINF = 0x7fffffffffffffff;
const double PI = acos(-1.0);
const double eps = 1e-10;
int v[200005];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &v[i]);
    v[i] += i;
  }
  sort(v + 1, v + 1 + n);
  for (int i = 2; i <= n; i++) {
    if (v[i] == v[i - 1]) {
      return !printf(":(");
    }
  }
  for (int i = 1; i <= n; i++) printf("%d ", v[i] - i);
}
