周赛3题目

Description

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

You are given x and y, please calculate f_n 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 f_n modulo 1000000007(10⁹ + 7).

Sample Input

Input

2 33

Output

1

Input

0 -12

Output

1000000006

Hint

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).

#include<stdio.h>#include<string.h>#define N 1001int main(){  int n,m,i,j,k;  int a[20];  while(~scanf("%d%d",&n,&m))  {    a[1]=n;    a[2]=m;    scanf("%d",&k);    for(i=3;i<=6;i++)    {     a[i]=a[i-1]-a[i-2];    }    a[0]=a[6];    printf("%d\n",((a[k%6]%1000000007)[phone])%1000000007);  }  return 0;}