题解 | #尼科彻斯定理#

import java.util.Scanner;

public class Main {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    while (sc.hasNext()) {
        int m = sc.nextInt();
        int start = m * m + 1 - m;
        StringBuilder sb = new StringBuilder();
        while (m-- > 0) {
            sb.append(start).append("+");
            start = start + 2;
        }
        System.out.println(sb.substring(0, sb.length() - 1));
    }
}

}