题解 | #截取字符串#

const readline = require('readline');
const rl = readline.createInterface({
    input:process.stdin,
    output:process.stdout
});
let arr = []
rl.on('line',(line) => {
    arr.push(line)
})
rl.on('close',()=>{
    console.log(arr[0].slice(0,arr[1]))
})