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

You are given x and y, please calculate f_n modulo1000000007 (10⁹?+?7).

The first line contains two integers x andy (|x|,?|y|?≤?10⁹). The second line contains a single integern (1?≤?n?≤?2·10⁹).

Output a single integer representing f_n modulo1000000007 (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).

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;
}