/in/foo.cc: In function 'void Output(std::vector<int>)':
/in/foo.cc:7:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < vec.size(); i++)
                  ~~^~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:77:10: error: 'gets_s' was not declared in this scope
  gets_s(s);
          ^