I submitted a solution for the problem: E. Bertown roads My submission is: 289121858

ideone Link of the same submission: https://ideone.com/Pn4Wdh

The checker comment I got is:

wrong output format Unexpected end of file — int32 expected

Input:

6 8
1 2
2 3
1 3
4 5
4 6
5 6
2 4
3 5

Participant's output:

1 2
1 3

Jury's Answer:

6 4
4 5
5 6
5 3
3 2
2 1
1 3
2 4

But if I run the same code with same input on online compilers and my machine, it produces correct output (N lines). You can check the ideone link I provided, even this one producing the correct output!

I even tried changing the code and replaced the map with set. Here is that submission: 289122463

But the same issue occurs. My code produces only two lines on codeforces but N lines on other compilers.

What am I missing?