Почему nullpointer, где ошибка?
package com.javarush.task.task07.task0708;
import java.util.*;
import java.io.*;
public class Solution {
private static ArrayList<String> strings;
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
for (int i = 0; i < 5; i++){
String s = reader.readLine();
strings.add(s);
}
String s = strings.get(0);
int max = s.length();
String m = null;
for (int i = 1; i < strings.size(); i++){
s = strings.get(i);
if (s.length() > max){
max = s.length();
m = strings.get(i);
}
else{
break;
}
}
ArrayList<String> list = new ArrayList<String>();
list.add(m);
String b = null;
for (int i = 0; i < strings.size(); i++){
b = strings.get(i);
if (b.length() == max){
list.add(b);
}
else{
break;
}
}
for (int i = 0; i < list.size(); i++){
System.out.println(list.get(i));
}
}
}