题解 | 整数的十位

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

void async function(){
    const lines=await readline()
    const a=Math.floor((parseInt(lines)/10)%10)

    console.log(a)
    rl.close()
}()