func_code_string: #include <bits/stdc++.h>   using namespace std;   long long mod = 1e9 + 7;   int main() {     long long n = 1, k = 1;     int t;     cin >> t;     for (int i = 1; i <= t; i++) {       n %= mod;       k %= mod;       n *= 27;       k *= 7;     }     while (n < k) n += mod;     n -= k;     cout << n % mod << endl;   }   