Write a simple sequence-number system through which three concurrent processes, P1, P2, and P3, each obtain unique integers in the range [1, 500]. Use the fork() call to create P, P2, and P3. Given a file, F, containing a single number, each process must perform the following steps:

a. Open F

b. Read the sequence number N from the file

c. Close F

d. Output N and the process' PID (either on screen or test file)

e. Increment N by 1

f. Open F

g. Write N to F

h. Close F.

Describe the behavior of your program and explore the reason for this behavior. Provide evidence for your conclusion in form of test-output. You must clearly document your code.