PROGRAMMING:"Smart students"

Problem Description: a professor of logic has three very intelligent students who are good at reasoning and mental arithmetic, Alice, Bob and Charles. One day the professor gave them a question. The professor pasted a note on everyone's forehead, and each note wrote a positive integer. Alice, Bob and Charles were 3, 5 and 8 respectively, and told the students that the sum of some two numbers was equal to the third. Each student could only see the positive integer on the heads of the other two students, but could not see his own.
The order of the professor's questions is Alice --- Bob Charles Alice... After several questions, when the professor asked Charles again, Charles showed a proud smile and accurately reported the number on his head.
###Input format:
Enter the numbers on Alice, Bob and Charles
###Output format:
When the professor asked a few questions, the person who answered the question guessed the number on his head.
###Input example:
Here is a set of inputs. For example:
```in
3，5，8
```
###Output example:
The corresponding output is given here. For example:
```out
six
```







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