/in/foo.cc: In function 'int compare(std::string, std::string)':
/in/foo.cc:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     for (int i = 0; i < a.size(); ++i) {
      |                     ~~^~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:75:8: error: expected '(' before 'N'
   75 |     if N =='1')
      |        ^
      |        (