#include <bits/stdc++.h>
using namespace std;
const int inf = 0x20202020;
const int mod = 1000000007;
template <class T>
inline void read(T &x) {
  bool fu = 0;
  char c;
  for (c = getchar(); c <= 32; c = getchar())
    ;
  if (c == '-') fu = 1, c = getchar();
  for (x = 0; c > 32; c = getchar()) x = x * 10 + c - '0';
  if (fu) x = -x;
};
template <class T>
inline void read(T &x, T &y) {
  read(x);
  read(y);
}
template <class T>
inline void read(T &x, T &y, T &z) {
  read(x);
  read(y);
  read(z);
}
template <class T>
inline void read(T &x, T &y, T &z, T &q) {
  read(x);
  read(y);
  read(z);
  read(q);
}
const int DX[] = {1, 0, -1, 0}, DY[] = {0, 1, 0, -1};
long long powmod(long long a, long long b) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long powmod(long long a, long long b, long long mod) {
  long long res = 1;
  a %= mod;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
const int N = 311111, M = 111111;
int l, m, n, t, C;
int a[N], p[N], ans[N];
inline bool cmp(const int &x, const int &y) { return a[x] < a[y]; }
int main() {
  scanf("%d", &n);
  for (int i = (1); i <= (n); ++i) scanf("%d", &a[i]), a[i] += i;
  for (int i = (1); i <= (n); ++i) p[i] = i;
  sort(p + 1, p + 1 + n, cmp);
  for (int i = (1); i <= (n); ++i) ans[i] = a[p[i]] - p[i] + (p[i] - i);
  for (int i = (1); i <= (n - 1); ++i)
    if (ans[i] > ans[i + 1]) {
      puts(":(");
      return 0;
    }
  for (int i = (1); i <= (n); ++i) printf("%d ", ans[i]);
  puts("");
  return 0;
}
