题解 | #尼科彻斯定理#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int m = sc.nextInt();
        int total = m * m * m;
        for (int i = 1; i <= total; i++) {
            if (i % 2 != 0 && (2 * (m - 1) + i + i) * m * 0.5 == total) {
                for (int j = 0; j < m - 1; j++) {
                    System.out.print(i + "+");
                    i = i + 2;
                }
                System.out.print(i);
                break;
            }
        }
    }
}