need hint

I did this task in different way because i can not understand debug mode now. Could you find error which cause that last requirement is not good?

I suggest you spend time learning techniques to test/debug code. You will not be able to solve these without the ability to do some basic troubleshooting, like adding sys.out.println's around your code to understand what is going on.

Here is a quick troubleshoot mode. See that I changed to remove user inputs and programmed in an array. I also put sys.out statements through the code to see what is happening:

public class Solution {
        public static void main(String[] args) throws IOException {
            //BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            int[] nums = {1,2,3,3,4,4,4,5,6,6};

            ArrayList<Integer> count = new ArrayList<>();
            ArrayList<Integer> num = new ArrayList<>();

            for(int i = 0; i<10; i++){
                /* num.add(Integer.parseInt(reader.readLine())); */
                num.add(nums[i]);
            }

            int a = 1;

            for(int i=0; i<num.size(); i++){
                for(int j = i+1; j < 9; i++) {
                    System.out.print("Checking values: " +num.get(i) + " and " + num.get(i+1));
                    if (num.get(i).equals(num.get(i + 1))) {
                        System.out.println("? Match!");
                        a++;
                    } else {
                        System.out.println("? Not a match. adding count of " + a + " to count list");
                        count.add(a);
                        a = 1;
                    }
                }

                count.add(a);
                System.out.println("count now: " + count);
            }
            System.out.println(Collections.max(count));

            //write your code here

        }
    }

when i run it this is the output: Checking values: 1 and 2? Not a match. adding count of 1 to count list Checking values: 2 and 3? Not a match. adding count of 1 to count list Checking values: 3 and 3? Match! Checking values: 3 and 4? Not a match. adding count of 2 to count list Checking values: 4 and 4? Match! Checking values: 4 and 4? Match! Checking values: 4 and 5? Not a match. adding count of 3 to count list Checking values: 5 and 6? Not a match. adding count of 1 to count list Checking values: 6 and 6? Match! Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 10, Size: 10 at java.util.ArrayList.rangeCheck(ArrayList.java:657) at java.util.ArrayList.get(ArrayList.java:433) at com.codegym.task.task01.task0108.Solution.main(Solution.java:33)

line 30 in my code is never reached. The code reaches the inner for loop and continues until it errors out when trying to access index 10. I do see, through the output, that a max count of 3 is added to the count list, which is correct, so your code is close to completion. Another problem is that you created an infinite loop with this line:

for(int j = i+1; j < 9; i++) {

The loop only exits when j < 9, but you only increment i with the i++. J will never reach 9 and when you fix the index error, you will still be left with the infinite loop.