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|≤109). The second line contains a single integer n (1≤n≤2·109).
Output a single integer representing fn modulo 1000000007 (109+7).
2 3
3
1
0 -1
2
1000000006
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).