https://www.acmicpc.net/problem/11721
const fs = require('fs')
const input = fs.readFileSync('/dev/stdin').toString().trim()
const solution = (input) => {
let arr = ''
for(let i=0; i<input.length; i+=10){
arr += '\n' + input.slice(i, i+10)
}
return arr.slice(1)
}
console.log(solution(input))
const input = 'Baekjunonline'
const solution = (input) => {
return input.split('')
.map((e, i) => (i % 10 === 0 ? '\n' : '') + e)
.join('').trim()
}
console.log(solution(input));