/in/foo.cc:42:1: error: stray '\342' in program
  
 ^
/in/foo.cc:42:2: error: stray '\200' in program
  
  ^
/in/foo.cc:42:3: error: stray '\203' in program
  
   ^
/in/foo.cc: In function 'std::vector<int> mul(std::vector<int>&, std::vector<int>&)':
/in/foo.cc:13:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < B.size(); i++)
                     ~~^~~~~~~~~~
/in/foo.cc:14:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j < A.size(); j++)
                         ~~^~~~~~~~~~
/in/foo.cc:18:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < C.size(); i++) {
                     ~~^~~~~~~~~~