func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, i, m = 1000000007, a, b;   int main() {     cin >> n;     a = 1, b = 1;     for (i = 0; i < 3 * n; i++) a = (a * 3) % m;     for (i = 0; i < n; i++) b = (b * 7) % m;     cout << (a - b + m) % m;     return 0;   }   