#include <bits/stdc++.h>
using namespace std;
template <class A, class B>
inline bool mina(A &x, B y) {
  return (x > y) ? (x = y, 1) : 0;
}
template <class A, class B>
inline bool maxa(A &x, B y) {
  return (x < y) ? (x = y, 1) : 0;
}
template <class A, class B>
inline A geta(A &x, const B y) {
  A t = x;
  x = y;
  return t;
}
int N;
int A[(200004)];
int main() {
  {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
  };
  cin >> N;
  for (int _b = (N), i = (0); i < _b; ++i) {
    int a;
    cin >> a;
    A[i] = a + i;
  }
  sort(A, A + N);
  int ok = 1;
  for (int _b = (N), i = (1); i < _b; ++i)
    if (A[i - 1] >= A[i]) ok = 0;
  if (ok)
    for (int _b = (N), i = (0); i < _b; ++i) printf("%d ", A[i] - i);
  else
    printf(":(\n");
  return 0;
}
