func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = 2147483647;   const long long LLINF = 9223372036854775807;   int main() {     int n;     cin >> n;     long long mod = 1000000009;     if (n == 2) cout << 10, exit(0);     long long b = 5, g = 1, r = 6;     long long fb = 2, fg = 2, t = 4;     for (int i = 0; i < n / 2 - 2; ++i) {       b = r + 3 * g * (t + 1);       g = (g * (1 + t)) % mod;       r = (b + g) % mod;       fb = (t + fg * 2) % mod;       fg = (fg * 2) % mod;       t = (fg + fb) % mod;     }     long long ans = ((r * r + 1) * 2) % mod;     cout << ans;     return 0;   }   