The issue with test case 6 is how the problem is formulated:

The original problem statement says that order matters, but test case 6 behaves as if order does not matter.

public class Solution {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int t = sc.nextInt();
    Set<String> set = new HashSet<>();
    for (int i = 0; i < t; i++) {
        String a = sc.next();
        String b = sc.next();
        String key = (a.compareTo(b) <= 0) ? (a + " " + b) : (b + " " + a);
        set.add(key);
        System.out.println(set.size());
    }
}

}

import java.io.; import java.util.; import java.text.; import java.math.; import java.util.regex.*;

public class Solution {

public static void main(String[] args) { Scanner s = new Scanner(System.in); int t = s.nextInt(); String [] pair_left = new String[t]; String [] pair_right = new String[t];

    for (int i = 0; i < t; i++) {
        pair_left[i] = s.next();
        pair_right[i] = s.next();
    }
    HashSet<String> set = new HashSet<String>();
    for(int i=0; i<t; i++){
        String pair = pair_left[i] + " " + pair_right[i];
        set.add(pair);
        System.out.println(set.size());
    }



}

}

Test Case 5 is wrong as the expected output parsed incorrectly. e.g. around line 192 and 193 fh kg ni aa the test case treated it is the same as line 177 kg ni Please fix it. Thanks.

The testcase expected output provided for testcase 5 is wrong according to my findings, i have cross verified the outcome using eclipse to understand the difference.

Can anyone help in moving to the next question, without having to solve this question as there is a bug in the expected output