5564: Jzzhu and Sequences

内存限制:256 MB 时间限制:2 S
题面:传统 评测方式:文本比较 上传者:
提交:0 通过:0

题目描述

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).