/in/foo.cc: In function 'void dts::dfs(int, int, int)':
/in/foo.cc:54:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<e[now].size();i++)
                ~^~~~~~~~~~~~~~
/in/foo.cc: In function 'void dts::calc(int, int)':
/in/foo.cc:87:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<e[now].size();i++)
                ~^~~~~~~~~~~~~~