Problem2735--Jzzhu and Sequences

2735: Jzzhu and Sequences

Time Limit: 2 Sec  Memory Limit: 256 MB
Submit: 0  Solved: 0
[Submit] [Status] [Web Board] [Creator:]

Description

time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

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).

Input

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

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

Examples
Input
2 3
3
Output
1
Input
0 -1
2
Output
1000000006
Note

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).

Source/Category