Problem: 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. 

Input

The input will have a single line containing four integers in this order: x, y, a, b. (1 ≤ x, y ≤ 1000, 1 ≤ a, b ≤ 2·109, a ≤ b).

Output

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.

Examples

Input

2 3 6 18


Output

3

Note

Let's look at the bricks from a to b (a = 6, b = 18). The bricks colored in red are numbered 6, 8, 10, 12, 14, 16, 18. The bricks colored in pink are numbered 6, 9, 12, 15, 18. The bricks colored in both red and pink are numbered with 6, 12 and 18. 

Solution (in JAVA):

Solution:


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;


public class Main {
    public static void main(String[] args) throws IOException{
        Reader.init(System.in); 
        PrintWriter out = new PrintWriter(System.out);
        TaskA solver = new TaskA();
        solver.solve(out);
        out.close();
    }
}

class TaskA{
    void solve(PrintWriter out) throws IOException{
        int x = Reader.nextInt();
        int y = Reader.nextInt();
        int a = Reader.nextInt();
        int b = Reader.nextInt();
        int z = commonMultiple(x, y);
        
        System.out.println(b/z - (a-1)/z);
    }
    public static int commonDivisor(int n,int m){
        
        while(n%m!=0){
        int temp=n%m;
        n=m;
        m=temp;
        }
        return m;
        }
        
        public static int commonMultiple(int n,int m){
        return n*m/commonDivisor(n,m);
        }
}


class Reader {
    static BufferedReader reader;
    static StringTokenizer tokenizer;

    /** call this method to initialize reader for InputStream */
    static void init(InputStream input) {
        reader = new BufferedReader(
                     new InputStreamReader(input) );
        tokenizer = new StringTokenizer("");
    }

    /** get next word */
    static String next() throws IOException {
        while ( ! tokenizer.hasMoreTokens() ) {
            //TODO add check for eof if necessary
            tokenizer = new StringTokenizer(
                   reader.readLine() );
        }
        return tokenizer.nextToken();
    }
    
    static String nextLine() throws IOException{
        return reader.readLine();
    }

    static int nextInt() throws IOException {
        return Integer.parseInt( next() );
    }
    
    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }
    
    static double nextDouble() throws IOException {
        return Double.parseDouble( next() );
    }
}