stop = True
help = '''Command List
EXIT --- Shutdown the program
HELP --- Get the list of all available commands
ECHO --- Print the given message to the screen'''

while stop:
    command = input(">>>")

    if command == "EXIT":
        stop = False
    elif command == "HELP":
        print(help)
    elif command.startswith("ECHO "):
        print(command[5:])
    else:
        print(f"Command {command} not found.")