Exam Results - Code Should Split Results In Stars In 4 Categories

I'm doing a program where a user enters in exam results for students. Once he's entered the code, the code should split the results in stars in 4 categories.

I am working with a while loop that prints out infinite results. What I want to do is, if the user enters 2 digits, say "12", it should output 1 "*".

If the user enters "21" and "22", it should output "**".

There are 4 categories of marks which are marked with ints range1, range2, range3 and range4, which are user enter digits. Part 1 of the code is to split the user entered digits into its correct ranges. the ranges are 0-29, 30-39, 40-69 and 70-100. I've done the part where when the user enters a digit, it goes into the correct variable. After that when the user enters a digit over 100, the enter results should show up as stars. For example

Enter number =

21
22
44
66
44
23
11
111 (the 111 is where the program breaks and moves on)

So it should then display

0-29 ****

30-39

40-69 ***

70-100

Whatever I'm trying, it displays an infinite amount of stars. If I try to use break, It only outputs a single star, no matter how many digits I enter

Here is the code

int mark = 0;
int range1 = 0, range2 = 0, range3 = 0, range4 = 0;
int count1 = 0, count2 = 0, count3 = 0, count4 = 0;
while (mark >=0 && mark <=100) {

[Code] .....

"The problem is with the while loop, the one above is something I was experimenting with "