/in/foo.cc: In function 'int main()':
/in/foo.cc:20:26: error: 'F' was not declared in this scope
   20 |         vector<Sta> nums(F.sign);
      |                          ^
/in/foo.cc:32:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Sta>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for (int i = 0; i < nums.size() && index < F.sign; ++i) {
      |                         ~~^~~~~~~~~~~~~
/in/foo.cc:42:22: error: 'sqrt' was not declared in this scope
   42 |         double sum = sqrt(dx * dx + dy * dy);
      |                      ^~~~
/in/foo.cc: At global scope:
/in/foo.cc:50:5: error: expected unqualified-id before 'return'
   50 |     return 0;
      |     ^~~~~~
/in/foo.cc:51:1: error: expected declaration before '}' token
   51 | }
      | ^