I received this message from System
Your solution 39098512 for the problem 990A significantly coincides with solutions alekseev.aleksei/39090526, GustavK/39098512. Such a coincidence is a clear rules violation. Note that unintentional leakage is also a violation. For example, do not use ideone.com with the default settings (public access to your code). If you have conclusive evidence that a coincidence has occurred due to the use of a common source published before the competition, write a comment to post about the round with all the details. More information can be found at http://codeforces.com/blog/entry/8790. Such violation of the rules may be the reason for blocking your account or other penalties.
But I didn't cheat and it is impossible that anyone took my solution. The solution mentioned is not even similar to mine, it is in Java and my is in C#! There is absolutely not a chance we copied each other. And how can "Such a coincidence" be a rule violation? How am I supposed to write code avoiding such a coincidence to not break the rules!?
So do I need to do anything to fix this or can I just ignore it? Is there a chance I will be blocked if this happens again?