The "Link" computers are located in RNS 202 and RNS 203. They run Linux, instead of OS/X (Mac) or Windows. You should be able to log in to any of those computers with your St. Olaf username and password.

Navigate to find a terminal application. It may be named Terminal or XTerm. Click on it to open up a terminal window.

The terminal window provides a "command-line" prompt for running programs: you can type in the name of a program, and it will run that program if available.
Enter the program name idle3 . A new window should appear like this:

The characters >>> are a prompt in idle3 for you to enter Python3 language expressions (this is the programming language we will use in CS 121). Enter the language expressions from one of the problems below.

Note: If this is the first time you have used idle3, here are a few things to try in order to get familiar with it.

• Type in the characters print("Hello, world!") , then press the enter/return key. You should see the characters Hello, world appear on the next line, followed by another >>> prompt.
  

• Type in the characters s = input("What is your name? ") . You should see the charactes What is your name? printed on the following line -- it's a prompt! -- giving you an opportunity to answer that question.
  

• Next, type in the characters print("Hi,", name) , and press enter/return. This should print the characters Hi, and your name on the next line, followed by the >>> prompt
  

• Finally, enter this multi-line expression:

      num = int(input("Enter an integer: "))
      if num < 0:
      	print("negative")
      else:
      	print("non-negative")
  
  

  After the first of these lines, you'll be prompted for an integer, and you'll see the >>> prompt again after you enter that integer. But the >>> prompt will not appear immediately after the following lines, until you enter a blank line after print("non-negative"). This is because idle3 recognizes that multiple lines are needed for the computer instruction that begins with if.

  Your output should look something like this:
  

  Note: Python expects certain indenting for certain kinds of instruction, and idle3 ordinarily provides appropriate indenting you want automatically. However, the else: line needs to appear at the beginning of the line instead of being lined up with the print instructions. To locate the else: at the beginning of the line, enter a backspace/delete character just before you enter those characters else: .

• If you make a mistake, you may get a red error message, for example,
    
  If you use the arrow keys or mouse to start changing the erroneous lines, idle3 will provide a new copy of those lines for you to continue: