Codeforces Round #257 (Div. 2) B Jzzhu and Sequences

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

You are given x and y, please calculate f_n modulo1000000007 (10 ⁹ + 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 f_n modulo1000000007 (10 ⁹ + 7).

Sample test(s)

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 (10 ⁹ + 7) equals(10 ⁹ + 6).

详见代码。

。。

#include<iostream>
using namespace std;
#define  modulo 1000000007
int main()
{
  __int64 q[6];
  int m,n;
    int k;
  while(~scanf("%d%d",&m,&n))
  {
     q[1]=m;
   q[2]=n;
   q[3]=n-m;
   q[4]=-m;
   q[5]=-n;
   q[0]=m-n;
   cin>>k;
   k=k%6;
   while(q[k]<0)
     q[k]=q[k]+modulo;

     printf("%I64d\n",q[k]%modulo);
  }
return 0;
}