This works but not according to solution...

This won't work. Alrdy tried that with this solution you'll need to make i<11 for full check of your inputs. Seems like You have to exceed max index.

Full check needs 9 compares. Have you tried to remove try-catch block?

Move listaSEQ.add(seq); to the end of the FOR loop.

package pl.codegym.task.task08.task0812; import java.io.*; import java.util.ArrayList; import java.util.Collections; public class Solution { public static void main(String[] args) throws IOException { //tutaj wpisz swój kod ArrayList<Integer> lista = new ArrayList<Integer>(); ArrayList<Integer> listaSEQ = new ArrayList<Integer>(); BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); for (int i= 0;i<10;i++) { String str = reader.readLine(); lista.add(Integer.parseInt(str)); } //dodawanie elementów int seq = 1; for (int i=1;i<10;i++) { if (lista.get(i) == lista.get(i-1)){ seq++; listaSEQ.add(seq); } if (lista.get(i) != lista.get(i-1)){ seq=1; } } int max = Collections.max(listaSEQ); System.out.println(max); } } I've changed it a little bit but now it won't accept 1 req :D seems like this task is broken... Can someone share their code :> I want my dark matter.

First condition (requairement)? I have the same as you: System.out.println(max); (max int type)

Moved it ... Still not working.

Yes, you placed add method in a right place. Now results are correct, I think. What condition fails?

I got this somehow "==" does not operate on higher numbers than 127. Probably cause one is method and second one is operator. My first code worked well when I've changed this "little" bug.

Hmm..., interesting. So give equals() method in place of ==. lista.get(i).equals(lista.get(i-1));

Wow! Nice :) Good job! And why not else in place of the second if?

Seems like operator works on "short" types. BUT method "equals" compares content of this value. Oh yeah, that's just bad habit ;)

this solution does not work if the sequence is at the end of the list, then one number is omitted. To avoid this issue adding a seq number to the array should happen after all if conditions:

int seq = 1;
for (int i = 0; i < list.size() - 1; i++) {
    if (list.get(i).equals(list.get(i + 1))) {
        seq++;
    }
    if (!list.get(i).equals(list.get(i + 1))) {
        seq = 1;
    }
    listSeq.add(seq);
}