Programming/Maths Problem

[ahref]

Hi,

Was wondering if anyone could help me with a mathsy programmy problem. Its been driving me nuts:

Given an infinite number of colums, where odd numbered columns have x cells and even numbered columns have y cells. Each cell can hold one object, how do i figure out the column number of the nth item.

For further clarification and example;
x = 4
y = 3


At the moment i do some stupid while loop to work this out, Id love it if there was a one liner, or simple maths formula. Speed is essential here

Thanks for your help guys

[Night_Runner]

You could do something like this http://ge.tt/8F1qJO6?c

[ahref]

How the hell did you figure that out ?