hdoj-1005 找规律

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner ss=new Scanner(System.in);
        short a=ss.nextShort();
        short b=ss.nextShort();
        int n=ss.nextInt();
        while (a!=0 && b!=0 && n!=0) {
            System.out.println(f(n%49, a, b));
            a=ss.nextShort();
            b=ss.nextShort();
            n=ss.nextInt();
        }
        ss.close();
    }
    private static byte f(int n,short a,short b)
    {
        if(n==1)
            return 1;
        if(n==2)
            return 1;
        return (byte)((f(n-1, a, b)*a+f(n-2, a, b)*b)%7);
    }
}