/in/foo.cc: In function 'std::vector<int> sequencemultiply(std::vector<int>, std::vector<int>)':
/in/foo.cc:48:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < a.size(); i++)
                  ~~^~~~~~~~~~
/in/foo.cc: In function 'bool isinfinitesequence(std::vector<int>, std::vector<int>)':
/in/foo.cc:77:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < c.size(); i++)
                  ~~^~~~~~~~~~