### Number Sequence

Time Limit: 1000 ms Memory Limit: 65535 KiB

#### Problem Description

A number sequence is defined as follows:
f(1) = 1, f(2) = 1, f(n) = (A * f(n - 1) + B * f(n - 2)) mod 7.
Given A, B, and n, you are to calculate the value of f(n).

#### Input

The input consists of multiple test cases. Each test case contains 3 integers A, B and n on a single line (1 <= A, B <= 1000, 1 <= n <= 100,000,000). Three zeros signal the end of input and this test case is not to be processed.

#### Output

For each test case, print the value of f(n) on a single line.

#### Sample Input

1 1 3
1 2 10
0 0 0

#### Sample Output

2
5

ZJCPC2004