Problem 1005. -- Number Sequence
HDU_1005: Number SequenceTime Limit: 1000 MS Memory Limit: 32 MB   64bit IO Format: %I64d
Submitted: 613 Accepted: 173
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).
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.
For each test case, print the value of f(n) on a single line.