func_code_string: #include <bits/stdc++.h>   const long long P = 1000000007;   long long N, oldA, oldB, oldC, oldD = 1, newA, newB, newC, newD;   int main() {     std::cin >> N;     for (int i = 1; i <= N; ++i) {       newA = (oldB + oldC + oldD) % P;       newB = (oldA + oldC + oldD) % P;       newC = (oldA + oldB + oldD) % P;       newD = (oldA + oldB + oldC) % P;       oldA = newA;       oldB = newB;       oldC = newC;       oldD = newD;     }     std::cout << newD;   }   