Determine if a product is positive, negative or zero without calculating it

Implement a program that reads two integer numbers and says if their product is positive, negative, or zero without doing the calculation.

Run the following combinations of examples to test that your program produces the same outputs:

• the first number is 0,

• the second number is 0,

• both numbers are 0,

• both numbers are positive,

• both numbers are negative,

• the first number is negative and the second is positive,

• the first number is positive and the second is negative.

>>> %Run
    Enter the first integer number: 0
    Enter the second integer number: -1
    The product is zero
>>> %Run 
    Enter the first integer number: 5
    Enter the second integer number: 0
    The product is zero
>>> %Run 
    Enter the first integer number: 0
    Enter the second integer number: 0
    The product is zero
>>> %Run 
    Enter the first integer number: 2
    Enter the second integer number: 7
    The product is positive
>>> %Run 
    Enter the first integer number: -4
    Enter the second integer number: -7
    The product is positive
>>> %Run 
    Enter the first integer number: -8
    Enter the second integer number: 3
    The product is negative
>>> %Run 
    Enter the first integer number: 10
    Enter the second integer number: -6
    The product is negative

Insist that the students test their programs by giving them example
test executions. Also pointing out that this way we try out all
possible combinations to test.