ROS subscriber example (C++)

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Hello every ROS users,

I followed the example as following link : Writing a Simple Publisher and Subscriber (C++)

But it not works when I type the command "rosrun beginner_tutorials", and it shows the message as this:

rosrun will locate PACKAGE and try to find
an executable named EXECUTABLE in the PACKAGE tree.
If it finds it, it will run it with ARGS.
Does someone know the problem? I would be thankful that anyone can help me. Thank you very much.