CodeForces 450-B. Jzzhu and Sequences

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).

#include<iostream>
#include<stdio.h>
#include<map>
using namespace std;
const int MOD = 1000000007;
typedef long long LL;
map<LL,LL > hehe;
int main()
{
    LL x,y,n;
    while(~scanf("%I64d%I64d",&x,&y))
    {
        hehe.clear();
        scanf("%I64d",&n);

        hehe[0] = ((x-y)%MOD+MOD)%MOD;
        hehe[1] = (x%MOD+MOD)%MOD;
        hehe[2] = (y%MOD+MOD)%MOD;
        hehe[3] = (-hehe[0]%MOD+MOD)%MOD;
        hehe[4] = (-hehe[1]%MOD+MOD)%MOD;
        hehe[5] = (-hehe[2]%MOD+MOD)%MOD;
        if(n<=5)
        {
            printf("%I64d\n",hehe[n]%MOD);
            continue;
        }
        n = n%6;
        printf("%I64d\n",hehe[n]%MOD);
    }
    return 0;
}