题解 | #尼科彻斯定理#

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void async function () {
    const m = parseInt(await readline());
    let res = [];
    if(m&1){
        res.push(m*m);
        while(res.length < m){
            res.unshift(res[0]-2);
            res.push(res[res.length-1]+2);
        }
    }else{
        res.push(m*m-1);
        res.push(m*m+1);
        while(res.length < m){
            res.unshift(res[0]-2);
            res.push(res[res.length-1]+2);
        }
    }
    console.log(res.join("+"));
}()