#include <bits/stdc++.h>
using namespace std;
int n, line[200000 + 1], error;
int main() {
  while (scanf("%d", &n) != EOF) {
    error = 0;
    int i, j, temp;
    for (i = 0; i < 200001; ++i) {
      line[i] = 0;
    }
    for (i = 0; i < n; ++i) {
      scanf("%d", &temp);
      line[i] = temp + i;
    }
    sort(line, line + n);
    for (i = 0; i < n - 1; ++i) {
      if (line[i] == line[i + 1]) {
        error = 1;
        break;
      } else {
      }
    }
    if (error == 1) {
      printf(":(\n");
    } else {
      for (i = 0; i < n; i++) {
        printf("%d ", line[i] - i);
      }
      printf("\n");
    }
  }
  return 0;
}
