Jzzhu has invented a kind of sequences, they meet the following property:

You are given x and y, please calculate fn modulo 1000000007 (109+7).

The first line contains two integers x and y (|x|,|y| \le 109). The second line contains a single integer n (1 \le n \le 2 \cdot 109).

Output a single integer representing fn modulo 1000000007 (109+7).

In the first sample, f2=f1+f3, 3=2+f3, f3=1.

In the second sample, f2=-1; -1 modulo (109+7) equals (109+6).