what is wrong here
package com.codegym.task.task07.task0713;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
/*
Playing Javarella
*/
public class Solution {
private static final List<Integer> list = null;
private static final List<Integer> list2 = null;
private static final List<Integer> List3 = null;
private static final List<Integer> list4 = null;
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
List<Integer> list = new ArrayList<Integer>();
List<Integer> list2 = new ArrayList<Integer>();
List<Integer> list3 = new ArrayList<Integer>();
List<Integer> list4 = new ArrayList<Integer>();
while (true)
{
String s = reader.readLine();
if (s.isEmpty()) break;
//int num=Integer.parseInt(s);
list.add(Integer.parseInt(s));
}
for(int i=0;i<list.size();i++) {
Integer x=list.get(i);
if (x % 3 == 0) // Check that the remainder is zero when we divide by 3
list3.add(x); // Add to list3
if(x % 2 == 0)
list2.add(x); // Add to the list2
else if (x % 2 != 0 && x % 3 != 0)
list4.add(x); //add to other list4
}
printList(list3);
printList(list2);
printList(list4);
}
public static void printList(List<Integer> list) {
for (Integer x: list)
{
System.out.println(x);
}
}
}