[백준] 9498번 : 시험 성적 - Javascript(자바스크립트)

https://www.acmicpc.net/problem/9498

const fs=require('fs')
let input=fs.readFileSync('/dev/stdin').toString()
var n=parseInt(input)
if(n>=90) console.log("A");
else if(n>=80) console.log("B");
else if(n>=70) console.log("C");
else if(n>=60) console.log("D");
else console.log("F");