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.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.StringTokenizer;


public class codeforces_b_wall {

    static class FastScanner{
        BufferedReader s;
        StringTokenizer st;
        
        public FastScanner(){
            st = new StringTokenizer("");
            s = new BufferedReader(new InputStreamReader(System.in));
        }
        
        public FastScanner(File f) throws FileNotFoundException{
            st = new StringTokenizer("");
            s = new BufferedReader (new FileReader(f));
        }
        
        public int nextInt() throws IOException{
            if(st.hasMoreTokens())
                return Integer.parseInt(st.nextToken());
            else{
                st = new StringTokenizer(s.readLine());
                return nextInt();
            }
        }
        
      public double nextDouble() throws IOException{
            if(st.hasMoreTokens())
                return Double.parseDouble(st.nextToken());
            else{
                st = new StringTokenizer(s.readLine());
                return nextDouble();
            }
        }
      
        public long nextLong() throws IOException{
            if(st.hasMoreTokens())
                return Long.parseLong(st.nextToken());
            else{
                st = new StringTokenizer(s.readLine());
                return nextLong();
            }
        }
        
        public String nextString() throws IOException{
            if(st.hasMoreTokens())
                return st.nextToken();
            else{
                st = new StringTokenizer(s.readLine());
                return nextString();
            }
            
        }
        public String readLine() throws IOException{
            return s.readLine();
        }
        
        public void close() throws IOException{
            s.close();
        }
        
    }
      private static FastScanner s = new FastScanner();   
      private static PrintWriter ww = new PrintWriter(new OutputStreamWriter(System.out));
     
   //   static int count=0;
     public static void main(String[] args) throws IOException 
     {
           long a=s.nextLong();
           long b=s.nextLong();
           long x=s.nextLong();
           long y=s.nextLong();
           long lc=lcm(a, b);
         // System.out.println("kyaa hua");
           long q1=x/lc;
            if(q1*lc<x)q1++;
           long show=lc*q1;
           
           long ans=0;
           
           ans=(y-show)/lc;
           
           ans++;
         //// System.out.println(" "+lc+"  "+show+"  "+ans);
           if(show==y) System.out.println(""+ans);
         else if(x!=lc && x==y || lc>y || show>y)
              System.out.println(""+0);
          else
              System.out.println(""+ans);
         s.close();
         ww.close();
     }
     public static long gcd(long a, long b){
        return b == 0 ? a : gcd(b,a%b);
    }
     public static long lcm(long a, long b)
{
    return a * (b / gcd(a, b));
}
   
    
}
/*zabardast swappimng of sorting
/*
    for(int h=0;h<n;h++)
        {  int temp,temp1,temp2;
             for(int y=h+1;y<n;y++)
           {
             if(a[y][2]>=a[h][2])
             {
              
             temp=a[y][2];                 //////sorting
             a[y][2]=a[h][2]; 
              a[h][2]=temp;
              temp1=a[y][0];
              a[y][0]=a[h][0];
              a[h][0]=temp1;
              temp2=a[y][1];
              a[y][1]=a[h][1];
              a[h][1]=temp2;
           
             }
           }  
        }
*/
/*
static final Point getMinMax(int[] array) {
        int min = array[0];
        int max = array[0];
        
        for (int index = 0, size = array.length; index < size; ++index, ++index) {
            int value = array[index];
            
            if (index == size - 1) {
                min = min(min, value);
                max = max(max, value);
            } else {
                int otherValue = array[index + 1];
                
                if (value <= otherValue) {
                    min = min(min, value);
                    max = max(max, otherValue);
                } else {
                    min = min(min, otherValue);
                    max = max(max, value);
                }
            }
        }
        
        return new Point(min, max);
    }
    
*/
/*

/// Demonstrate several Is... methods.
class IsDemo {
public static void main(String args[]) {
char a[] = {'a', 'b', '5', '?', 'A', ' '};
for(int i=0; i<a.length; i++) {
if(Character.isDigit(a[i]))                                   ///check if digit is present in string
System.out.println(a[i] + " is a digit.");
if(Character.isLetter(a[i]))
    System.out.println(num + " in binary: " +
Integer.toBinaryString(num));
System.out.println(num + " in octal: " +
Integer.toOctalString(num));
System.out.println(num + " in hexadecimal: " +
Integer.toHexString(num));
}
}
*/
/*
private static void findSubsets(int array[])
{
  int numOfSubsets = 1 << array.length; 

  for(int i = 0; i < numOfSubsets; i++)
 {
    int pos = array.length - 1;                                /////bitmask to find all sub sets
   int bitmask = i;

   System.out.print("{");
   while(bitmask > 0)
   {
    if((bitmask & 1) == 1)
     System.out.print(array[pos]+",");
    bitmask >>= 1;
    pos--;
   }
   System.out.print("}");
 }
}
*/

/*   no of DIVISORSSSSSS
 public ArrayList<Integer> get(int x){
            ArrayList<Integer> divisors = new ArrayList<>();
            for(int i = 1; i * i <= x; i++){
                if(x % i == 0){
                    divisors.add(i);
                    if(i * i != x){
                        divisors.add( x / i);
                    }
                }
            }
            
*/
/*  //// find sum of multiple of a value below limit// ----> (l*(n+1))/2
  public static long getSequenceSum(long value, long limit) {
long q = (limit - 1) / value;
long ans = ((value*q)*(1+q) )/ 2;
return ans;
}
*/
/*// largest prime factor of a no
 public static long largestPrimeFactor(long n) {

        // largest composite factor must be smaller than sqrt
        long sqrt = (long)Math.ceil(Math.sqrt((double)n));

        long largest = -1;

        for(long i = 2; i <= sqrt; i++) {
            if(n % i == 0) {
                long test = largestPrimeFactor(n/i);
                if(test > largest) {
                    largest = test;
                }
            }
        }

        if(largest != -1) {
            return largest;
        }

        // number is prime
        return n;
    } 
*/
/*    // prime no using sieve of erostheneses
  public static void prime()
{
  boolean[] isPrime = new boolean[100000000+ 1];
         Arrays.fill(isPrime, true);

        // mark non-primes <= N using Sieve of Eratosthenes
        for (int i = 2; i*i <= 100000000; i++)
        {

             if (isPrime[i])
             {
                for (int j = i; i*j <= 100000000; j++) {
                    isPrime[i*j] = false;
                }
            }
        }
}

*/
/*//// largest common sequences
 public String lcs(String str1, String str2)
    {
        int l1 = str1.length();
        int l2 = str2.length();
 
        int[][] arr = new int[l1 + 1][l2 + 1];
 
        for (int i = l1 - 1; i >= 0; i--)
        {
            for (int j = l2 - 1; j >= 0; j--)
            {
                if (str1.charAt(i) == str2.charAt(j))
                    arr[i][j] = arr[i + 1][j + 1] + 1;
                else 
                    arr[i][j] = Math.max(arr[i + 1][j], arr[i][j + 1]);
            }
        }
 
        int i = 0, j = 0;
        StringBuffer sb = new StringBuffer();
        while (i < l1 && j < l2) 
     
 {
            if (str1.charAt(i) == str2.charAt(j)) 
            {
                sb.append(str1.charAt(i));
                i++;
                j++;
            }
            else if (arr[i + 1][j] >= arr[i][j + 1]) 
                i++;
            else
                j++;
        }
        return sb.toString();
    }
 
*/