//-----------------------------------------AC code-----------------------------------------//

#include<cstdio>
#include<algorithm>

using namespace std;

const int MAXN = 100005;
int n, a[MAXN];

int main(){
//  freopen("sort.in", "r", stdin);
//  freopen("sort.out", "w", stdout);
    scanf("%d", &n);
    for(int i = 1; i <= n; i++)
        scanf("%d", &a[i]), a[i] += i;
    sort(a+1, a+n+1);
    for(int i = 1; i <= n; i++)
        a[i] -= i;
    for(int i = 1; i < n; i++)
        if(a[i+1] < a[i]){
            printf(":(\n");
            return 0;
        }
    for(int i = 1; i <= n; i++)
        printf("%d\n", a[i]);
    return 0;
}