#include <bits/stdc++.h>
using namespace std;
const long long INF = 1 << 28;
const long long LINF = 1ll << 61;
inline long long getnum() {
  register long long r = 0;
  register bool ng = 0;
  register char c;
  c = getchar();
  while (c != '-' && (c < '0' || c > '9')) c = getchar();
  if (c == '-') ng = 1, c = getchar();
  while (c != ' ' && c != '\n') r = r * 10 + c - '0', c = getchar();
  if (ng) r = -r;
  return r;
}
template <class T>
inline void putnum(T x) {
  if (x < 0) putchar('-'), x = -x;
  register short a[20] = {}, sz = 0;
  while (x > 0) a[sz++] = x % 10, x /= 10;
  if (sz == 0) putchar('0');
  for (int i = sz - 1; i >= 0; i--) putchar('0' + a[i]);
}
inline void putsp() { putchar(' '); }
inline void putendl() { putchar('\n'); }
int n, a[200111];
int main() {
  n = getnum();
  for (int i = 1; i <= n; i++) a[i] = getnum(), a[i] = a[i] - (n - i + 1);
  sort(a + 1, a + n + 1);
  for (int i = 1; i < n; i++) {
    if (a[i] == a[i + 1]) {
      puts(":(");
      return 0;
    }
  }
  for (int i = 1; i <= n; i++) {
    putnum(a[i] + n - i + 1), putsp();
  }
  return 0;
}
