正则表达式即可

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

void async function () {
    // Write your code here
    let str = await readline();
    let all_words = str.match(/[a-zA-z]+/g);
    let res = all_words.reverse().join(' ');
    console.log(res);
}()