040000 tree 53e8f71a3a6fb5900843119bd1f630a573b132c6	greeter_client
040000 tree 866727b5c01a5e5f6fe2a05d08d0aa4c9ab1dc8d	greeter_server
040000 tree 3317cb4bb9a39793b9c5f15efacd47d80696572f	helloworld