/in/foo.cc: In function 'int main()':
/in/foo.cc:21:26: error: 'F' was not declared in this scope
   21 |         vector<Sta> nums(F.sign);
      |                          ^
/in/foo.cc: At global scope:
/in/foo.cc:51:5: error: expected unqualified-id before 'return'
   51 |     return 0;
      |     ^~~~~~
/in/foo.cc:52:1: error: expected declaration before '}' token
   52 | }
      | ^