Basically i have a loop, and i need to increase z by 30

**every time**y-x is greater than or equal to 1000.

X and Y are inputted by the user

the value of Z depends on the difference of x and y,

the loop only works when Y is greater than or equal to X

If there is another way to do this without loops, I'd be happy to consider it.

so for example

4500 - 4000 = 500, so Z = 0

4500 - 3500 = 1000, so Z = 30

2000 - 947 = 1053, so Z = 30

3500 - 1000 = 2500, so Z = 60

4000 - 900 = 3100, so Z = 90

10000 - 500 = 9500, so Z = 270

the answer should be the same for most C languages,

this is what i have - sometimes works but is very hit and miss:

//x and y already inputted double z = 0; while (y >= x) { y = y - x; if (y >= 1000) { z+=30; } }

but it doesn't work, even though I've been told it should work

any help?