/in/foo.cc: In function 'void dts::main()':
/in/foo.cc:151:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (ll i=0;i<x.size();i++)
               ~^~~~~~~~~
/in/foo.cc:156:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (i<x.size())
        ~^~~~~~~~~
/in/foo.cc: In function 'dts::ll dts::search(dts::ll)':
/in/foo.cc:130:2: warning: control reaches end of non-void function [-Wreturn-type]
  }
  ^