Java 平面圓形切割

題目:平面圓形切割

公式: N*N-N+2

import java.util.Scanner;
public class A042 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int n = sc.nextInt();
            System.out.println(n*n -n+2);
        }
    }
}