040000 tree 0f53f04fb2afbbbafeeac1ba969d92caf9203d54	greeter_client
040000 tree aa79398360bc8f27ba21eb79ef2f2e2dce0efb2e	greeter_server
040000 tree c2b489d036cd54f53b19dd702aec9ed73ba75f7c	helloworld