Codeforces round #257 (Div. 2/B)/codeforces1_ B _jzzhu and Sequences

B solution report

It's a regular question., x y z-x-y-Z.

Note that if the number is less than 0, you must first modulo the negative number and then modulo it. You cannot directly add mod, but it may still be a negative number.

The stamp code for me is kneeling ,,,

#include <iostream>#include <cstring>#include <cstdio>using namespace std;long long x,y,z;long long n;int main(){    cin>>x>>y;    cin>>n;    z=y-x;    long long t;    t=(n-1)/3;    if(t%2==0)    {        n%=3;        if(n==0)        {            if(z>=0)            cout<<z%1000000007;            else cout<<(z%1000000007+1000000007)%1000000007;        }        else if(n==1)        {            if(x>=0)            cout<<x%1000000007;            else cout<<(x%1000000007+1000000007)%1000000007;        }        else        {            if(y>=0)            cout<<y%1000000007;            else cout<<(y%1000000007+1000000007)%1000000007;        }    }    else    {        x=-x;        y=-y;        z=-z;        n%=3;if(n==0)        {            if(z>=0)            cout<<z%1000000007;            else cout<<(z%1000000007+1000000007)%1000000007;        }        else if(n==1)        {            if(x>=0)            cout<<x%1000000007;            else cout<<(x%1000000007+1000000007)%1000000007;        }        else        {            if(y>=0)            cout<<y%1000000007;            else cout<<(y%1000000007+1000000007)%1000000007;        }    }    return 0;}

Jzzhu and sequencestime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard output

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

You are givenXAndY, Please calculateFNModulo 1000000007 (109? +? 7 ).

Input

The first line contains two integersXAndY(|X| ,? |Y|? ≤? (109). The second line contains a single integerN(1? ≤?N? ≤? 2 · 109 ).

Output

Output a single integer representingFNModulo 1000000007 (109? +? 7 ).

Sample test (s) Input

2 33

Output

1

Input

0 -12

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 ).