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

void async function () {
    let str  = await readline()
    str = str+"00000000"
    while(str.length>8){
        console.log(str.substring(0,8))
        str = str.substring(8,str.length)
    }

}()

自己写的不是这个,这是从题解里看到的巧妙方法。补8个0是为了保证最后一行的输出一定是8位吧