answer.code: In function ‘int main()’:
answer.code:14:16: error: ‘to_string’ was not declared in this scope
   14 |         num += to_string(i);
      |                ^~~~~~~~~
answer.code:14:16: note: ‘std::to_string’ is only available from C++17 onwards
answer.code:15:12: error: ‘stoi’ was not declared in this scope
   15 |         if(stoi(num)/m*m == stoi(num)){
      |            ^~~~
answer.code:15:12: note: ‘std::stoi’ is only available from C++11 onwards