What determines the result of casting an int to enumerate when multiple names have the same value?

Question

What determines the result of casting an int to enumerate when multiple names have the same value?

Denial of responsibility. I do not condone this listing. This leads to confusion and a tendency to make mistakes. However, I am curious that I discovered an irregularity.

I used the following code ( fiddle here ):

enum Anims{ 
  Donkey = 1, Wonkey = 1, 
  Monkey = 2, Oinky  =2, 
  A = 3, B = 3, C = 3, bb = 4, aa = 4
}

foreach(Anims anim in Enum.GetValues(typeof(Anims)))
  Console.WriteLine((Anims)((int)anim));

The result that I expected was either that the declared values would be presented. Perhaps the values that were assigned last. Nothing of the kind happened. I also looked at the alphabetical order of the output. No ...

What is an algorithm that determines which integer will be enclosed in an enumeration if there are several values corresponding to it?

Conclusion: