Simple Array Sum

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 'simpleArraySum' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts INTEGER_ARRAY ar as parameter.
     */

    public static int simpleArraySum(List<Integer> ar) {
    // Write your code here
    int sum=0;
    int[] arr=new int[ar.size()];
    for (int i = 0; i < ar.size(); i++)
            arr[i] = ar.get(i);
    for(int j=0;j<arr.length;j++)
        sum += arr[j];
        return sum;
    }

}

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 arCount = Integer.parseInt(bufferedReader.readLine().trim());

        List<Integer> ar = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
            .map(Integer::parseInt)
            .collect(toList());

        int result = Result.simpleArraySum(ar);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}