1 1 3
1 2 10
0 0 0

2
5

import java.io.*;
import java.util.*;

public class Main
{  
    public static void main(String[] args) 
    {  
        Scanner input = new Scanner(System.in);  
        int a, b;  
        int n;  
        while (input.hasNext()) 
        {  
            a = input.nextInt();  
            b = input.nextInt();  
            n = input.nextInt();  
            if (a == 0 & b == 0 & n == 0)  
                System.exit(0);  
            int f[] = new int[50];  
            for (int i = 1; i < 50; i++) 
            {  
                if (i == 1 || i == 2) 
                {  
                    f[i] = 1;  
                } else 
                {  
                    f[i] = (a * f[i - 1] + b * f[i - 2]) % 7;  
                }  
            }  
            System.out.println(f[n % 49]);  
        }  
    }  
  
}