
const readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout
});
let input = [];
rl.on('line', function (line) {
input = [line];
}).on('close',function(){
str = input[0];
str1 = [...str]
str1.map(a => console.log(a))
});
map 을 사용해서 console.log로 하나씩 출력하면 됐다.