func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mod = 1000000007;   int a[1005];   int main() {     int x, y, n;     cin >> x >> y;     int a[10] = {-x, -y, x - y, x, y, y - x};     cin >> n;     int ans = (n + 2) % 6;     a[ans] %= mod;     if (a[ans] < 0) a[ans] += mod;     cout << a[ans] << endl;     return 0;   }   