answer.code:4:1: error: ‘::main’ must return ‘int’
    4 | void main()
      | ^~~~
answer.code: In function ‘int main()’:
answer.code:12:9: error: return-statement with no value, in function returning ‘int’ [-fpermissive]
   12 |         return;
      |         ^~~~~~
answer.code:28:17: error: return-statement with no value, in function returning ‘int’ [-fpermissive]
   28 |                 return;
      |                 ^~~~~~