const readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout
});
let input = [];
rl.on('line', function (line) {
input = line.split(' ');
}).on('close', function () {
str = input[0];
n = Number(input[1]);
console.log(str.repeat(n))
});
💡 repeat(count) : 문자열을 주어진 횟수(count)만큼 반복해 붙인 새로운 문자열을 반환