题解 | #尼科彻斯定理#

import java.io.*;
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        while(sc.hasNextInt()){
            System.out.println(fun(sc.nextInt()));
        }
    }

    public static String fun(int n){
        StringBuilder sb = new StringBuilder();
        int start = n * (n - 1) + 1;
        for(int i = 0; i < n; ++i){
            sb.append(start + i * 2);
            sb.append("+");
        }
        sb.deleteCharAt(sb.length()-1);
        return sb.toString();
    }
}