HDU1005

import java.util.Scanner;

/**

• Created by mac on 2018/12/1.
  */
  public class Main {
  public static void main(String[]args){
  Scanner input = new Scanner(System.in);
  int a,b,n;
  while(true){
  a = input.nextInt();
  b = input.nextInt();
  n = input.nextInt();
  if (a < 1 & a > 1000 & b < 1 & b > 1000 & b < 1 & a > 100000000)
  System.exit(0);
  if (a == 0 && b ==0 && n == 0) break;
  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]);
  }
  input.close();
  }
  }