A Short Counting Problem

Given two integers $A$ and $B$, find the count of integers $X \in [L, R]$ such that **at least** one of the following is true: - $X$ and $A$ are [coprime](https://en.wikipedia.org/wiki/Coprime_integers) - $X$ and $B$ are [coprime](https://en.wikipedia.org/wiki/Coprime_integers) ### Input - The first and only line of input contains four integers $A,B,L,$ and $R$: as given in the problem statement.