foo.cc:21:5: error: expected unqualified-id before ‘if’
   21 |     if(n>0)
      |     ^~
foo.cc:23:5: error: expected unqualified-id before ‘else’
   23 |     else
      |     ^~~~
foo.cc:25:5: error: expected unqualified-id before ‘return’
   25 |     return 0;
      |     ^~~~~~
foo.cc:26:1: error: expected declaration before ‘}’ token
   26 | }
      | ^