answer.code: In function ‘int min_cardinality(int)’:
answer.code:15:9: error: ‘move_inside’ was not declared in this scope
   15 |         move_inside(i);
      |         ^~~~~~~~~~~
answer.code:20:25: error: ‘press_button’ was not declared in this scope
   20 |             int press = press_button();
      |                         ^~~~~~~~~~~~
answer.code:25:13: error: ‘move_outside’ was not declared in this scope
   25 |             move_outside(j);
      |             ^~~~~~~~~~~~
answer.code:27:9: error: ‘move_outside’ was not declared in this scope
   27 |         move_outside(i);
      |         ^~~~~~~~~~~~
answer.code:36:1: warning: no return statement in function returning non-void [-Wreturn-type]
   36 | }
      | ^