#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-10;
const int maxn = 1e6 + 10;
const long long INF = 1e9;
const int logmaxn = 22;
int n, k;
int a[maxn];
int b[maxn];
int ans[maxn];
inline int f(int i) { return a[i] - (n - i - 1); }
bool cmp(int x, int y) { return f(x) < f(y); }
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cin >> n;
  for (int t = (0); t < (n); ++t) cin >> a[t], b[t] = t;
  sort(b, b + n, cmp);
  for (int i = n - 1; i >= 0; --i) {
    ans[i] = a[b[i]] - (i - b[i]);
  }
  bool ok = 1;
  for (int t = (0); t < (n); ++t) {
    if (ans[t] < 0) ok = 0;
    if (t + 1 < n && ans[t] > ans[t + 1]) ok = 0;
  }
  if (ok)
    for (int t = (0); t < (n); ++t) cout << ans[t] << " ";
  else
    cout << ":(";
}
