/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:16:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<e[x].size();i++)
              ~^~~~~~~~~~~~
/in/foo.cc: Assembler messages:
/in/foo.cc:52: Error: unsupported instruction `mov'