При компиляции выдает такую ошибку: Exception in thread "main" java.lang.NullPointerException at com.javarush.task.task07.task0701.Solution.max(Solution.java:29) at com.javarush.task.task07.task0701.Solution.main(Solution.java:15) Меняю return на list и max, выдает эту ошибку: Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 32 at com.javarush.task.task07.task0701.Solution.max(Solution.java:32) at com.javarush.task.task07.task0701.Solution.main(Solution.java:15) 
package com.javarush.task.task07.task0701;

import javax.jnlp.ClipboardService;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/*
Массивный максимум
*/

public class Solution {
    public static void main(String[] args) throws Exception {
        int[] array = initializeArray();
        int max = max(array);
        System.out.println(max);
    }

    public static int[] initializeArray() throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int[] list = new int[20];
        for (int i = 0; i < list.length; i++) {
            String s = reader.readLine();
            list[i] = Integer.parseInt(s);
        }
        return list;
    }

    public static int max(int[] array) {
        int max = array[0];
        for (int x: array) {
            if(array[x]>max)max=array[x];
        }
        return max;
    }
}