Hackkerank problem solving Grading students

 import java.io.*;

import java.math.*;

import java.security.*;

import java.text.*;

import java.util.*;

import java.util.concurrent.*;

import java.util.function.*;

import java.util.regex.*;

import java.util.stream.*;

import static java.util.stream.Collectors.joining;

import static java.util.stream.Collectors.toList;

class Result {

    /*

     * Complete the 'gradingStudents' function below.

     *

     * The function is expected to return an INTEGER_ARRAY.

     * The function accepts INTEGER_ARRAY grades as parameter.

     */

    public static List<Integer> gradingStudents(List<Integer> grades) {

        

        ArrayList<Integer> aa=new ArrayList<Integer>();

        for(int i=0;i<grades.size();i++){

            if(grades.get(i)<38){

                

                aa.add(grades.get(i));

            }

            else if(grades.get(i)>38 && grades.get(i)<=40){

               

                aa.add(Integer.valueOf(40));

            }

            else if((grades.get(i))%5==3){

                int a=grades.get(i);

                a+=2;

                aa.add(a);

            }

            else if((grades.get(i))%5==4){

                int b=grades.get(i);

                b=b+1;

                aa.add(b);

            }

            else {

               

                aa.add(grades.get(i));

            }

            

        }

            // Write your code here

        return aa;

    }

}

public class Solution {

    public static void main(String[] args) throws IOException {

        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int gradesCount = Integer.parseInt(bufferedReader.readLine().trim());

        List<Integer> grades = IntStream.range(0, gradesCount).mapToObj(i -> {

            try {

                return bufferedReader.readLine().replaceAll("\\s+$", "");

            } catch (IOException ex) {

                throw new RuntimeException(ex);

            }

        })

            .map(String::trim)

            .map(Integer::parseInt)

            .collect(toList());

        List<Integer> result = Result.gradingStudents(grades);

        bufferedWriter.write(

            result.stream()

                .map(Object::toString)

                .collect(joining("\n"))

            + "\n"

        );

        bufferedReader.close();

        bufferedWriter.close();

    }

}