Number Sequence

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]); 
            } 
        } 
    }