Voting for the location of the CIS-2107 tournament.

I don't know if multiple choices are necessary. I think they are. If a person wants to arrive and 2nd place is equally good, why should they have to choose?

In short, I'm waiting for reasonable ideas. What does anyone suggest?

Firstly, the numbers are exactly the same for me (I just multiplied each by two to make it easier to calculate later).
Secondly, a person has a vote worth n points. They can distribute these n points either to one application or divide them between two. Otherwise, they would have 2n points and gain an advantage over those who vote for only one city. In this case, the algorithm itself would contain an error – those who vote for two cities would have a greater influence on the voting than those who vote for one, which means unequal conditions for each participant in the voting.