AOJ803魔方

package contest;import java.util.Scanner;public class Main{    public static void main(String[] args) {        Scanner sc=new Scanner(System.in);        while(sc.hasNextInt()){            int a=sc.nextInt();            if(a==1){                System.out.println(1);            }else{                System.out.println(a*a*a-(a-2)*(a-2)*(a-2));            }        }    }}