/in/foo.cc: In function 'std::vector<int> FindMaxs(const std::vector<int>&)':
/in/foo.cc:12:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 1; i < vec.size() - 1; i++) {
                     ~~^~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:51:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < maxsA.size(); i++) {
                     ~~^~~~~~~~~~~~~~
/in/foo.cc:57:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < maxsB.size(); i++) {
                     ~~^~~~~~~~~~~~~~