many people thought main would be the first function to be called.
But there are some exceptions where other function get called
before main actually called.

class mine {
            public:
              mine()
              {
                   cout<<"Constructor called \n";
              }
 };

mine obj1;

int main() {
  cout<<"we are in main";

        return 0;
}

after running this first constructor will be called later main executed.