對於%需要注意的

1%x，就是1；

x%x=0;

開數組a[x]不是a[x],是a[0];

http://codeforces.com/contest/450/problem/B

B. Jzzhu and Sequences

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).

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 (109 + 7) equals (109 + 6).

最後處理注意下

#include<iostream>  
using namespace std;  
int main()
{
	long long n;

	long long a[100];
	cin>>a[1]>>a[2];
	cin>>n;
	a[3]=a[2]-a[1];
	a[4]=-a[1];
	a[5]=-a[2];
	a[0]=-a[3];
	
	int ss = n % 6;
    ss = a[ss];
    ss %= 1000000007;
    if (ss < 0)
        ss += 1000000007;
    printf("%d\n", ss);
}