A9090 | The Wall

Iahub and his friend Floyd have started painting a wall. Iahub is painting the wall red and Floyd is painting it pink. You can consider the wall being made of a very large number of bricks, numbered $1$ , $2$ , $3$ and so on.

Iahub has the following scheme of painting: he skips $x-1$ consecutive bricks, then he paints the $x$ -th one. That is, he'll paint bricks $x$ , $2·x$ , $3·x$ and so on red. Similarly, Floyd skips $y-1$ consecutive bricks, then he paints the $y$ -th one. Hence he'll paint bricks $y$ , $2·y$ , $3·y$ and so on pink.

After painting the wall all day, the boys observed that some bricks are painted both red and pink. Iahub has a lucky number $a$ and Floyd has a lucky number $b$ . Boys wonder how many bricks numbered no less than $a$ and no greater than $b$ are painted both red and pink. This is exactly your task: compute and print the answer to the question.

The input will have a single line containing four integers in this order: $x$ , $y$ , $a$ , $b$ . ( $1<=x,y<=1000$ , $1<=a,b<=2·10^{9}$ , $a<=b$ ).

Output a single integer — the number of bricks numbered no less than $a$ and no greater than $b$ that are painted both red and pink.