Main.cc:11:1: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type]
   11 | main(){
      | ^~~~
Main.cc: In function ‘int main()’:
Main.cc:30:3: error: ‘ans’ was not declared in this scope; did you mean ‘ans2’?
   30 |   ans*=2;
      |   ^~~
      |   ans2