/in/foo.cc: In function 'int main()':
/in/foo.cc:16:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |                 for(int i=0;i<at.size();i++)
      |                             ~^~~~~~~~~~
/in/foo.cc:18:9: error: expected primary-expression before '}' token
   18 |         }
      |         ^