Tom’s Paper Company Ltd wants to produce a payroll register using a program. The data entry clerk is required to enter data

for each employee, which comprises of: the employee number (integer), the employee last name (string), the hours worked
that week (integer), and the rate of pay per hour (real number), and the percentage (%) of income tax paid by the company
on behalf of the worker (integer). The last employee entry contains the number -999 only, which is used as a sentinel to mark
the end of all the employee data. The gross pay for each employee is to be calculated as hours worked multiplied by the rate
of pay. The total vat paid by the company is 15 percent of the gross pay.

so, first step: make a loop to read the input, and exit when the employee id = -999

To produce a payroll register using a program, you can use a programming language like Python or Java. Here's a step-by-step explanation of how you can achieve this:

1. Start by creating variables to store the total gross pay and the total VAT paid by the company. Initialize both variables to 0.

2. Set up a loop that will prompt the data entry clerk to enter employee data until the sentinel value (-999) is entered. For each employee, the data entry clerk should enter the employee number, last name, hours worked per week, rate of pay per hour, and the percentage of income tax paid by the company on behalf of the worker.

3. Inside the loop, calculate the gross pay for the current employee by multiplying the hours worked by the rate of pay per hour.

4. Calculate the VAT paid by the company as 15% of the gross pay.

5. Update the total gross pay and total VAT variables by adding the current employee's gross pay and VAT.

6. Continue with the next iteration of the loop until the sentinel value is entered.

7. Once the loop is complete, display the payroll register, including the employee number, last name, hours worked, rate of pay, gross pay, and VAT paid for each employee.

Here's a sample Python code snippet that demonstrates the implementation of the above steps:

```python
# Step 1
total_gross_pay = 0
total_vat_paid = 0

# Step 2 - Loop
while True:
# Step 2.1 - Get employee data from the data entry clerk
employee_number = int(input("Enter employee number (-999 to quit): "))
if employee_number == -999:
break

last_name = input("Enter employee last name: ")
hours_worked = int(input("Enter hours worked that week: "))
rate_of_pay = float(input("Enter rate of pay per hour: "))
tax_percentage = int(input("Enter percentage of income tax paid by the company: "))

# Step 3 - Calculate gross pay
gross_pay = hours_worked * rate_of_pay

# Step 4 - Calculate VAT
vat_paid = gross_pay * 0.15

# Step 5 - Update totals
total_gross_pay += gross_pay
total_vat_paid += vat_paid

# Step 6 (Continues with the next iteration)

# Step 7 - Display payroll register
print("Payroll Register:")
print("============================================================================================")
print("Employee Number\tLast Name\tHours Worked\tRate of Pay\tGross Pay\tVAT Paid")
print("============================================================================================")
# Display employee data here

# Finally, display the total gross pay and total VAT paid by the company
print("============================================================================================")
print("Total Gross Pay: ", total_gross_pay)
print("Total VAT Paid: ", total_vat_paid)
print("============================================================================================")
```

You can run this code and enter the required employee data as prompted by the program. Once you enter the sentinel value (-999), the program will display the payroll register, including the employee details, as well as the total gross pay and VAT paid by the company.