Problem:
Score : 300 points

Problem Statement

You are given four integers A, B, C, and D. Find the number of integers between A and B (inclusive) that can be evenly divided by neither C nor D.

Constraints

1\leq A\leq B\leq 10^{18}

1\leq C,D\leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B C D

Output

Print the number of integers between A and B (inclusive) that can be evenly divided by neither C nor D.

Sample Input 1

4 9 2 3

Sample Output 1

2

5 and 7 satisfy the condition.

Sample Input 2

10 40 6 8

Sample Output 2

23

Sample Input 3

314159265358979323 846264338327950288 419716939 937510582

Sample Output 3

532105071133627368

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long A = Long.parseLong(sc.next());
        long B = Long.parseLong(sc.next());
        long C = Long.parseLong(sc.next());
        long D = Long.parseLong(sc.next());
        long count =  (B/C - A/C) + (B/D - A/D) - (B/(C*D/saiyaku(C,D)) - A/(C*D/saiyaku(C,D))); 
        System.out.println(B-A-count+1);
    }
    
    public static long max(long x, long y) {
        if(x <= y) {
            return y;
        }else {
            return x;
        }
    }
    
    public static long saiyaku(long x, long y) {
        long w = 0;
        if(x < y) {
            w = x;
            x = y;
            y = w;
            return saiyaku(x, y);
        }
        w = y;
        y = x % y;
        x = w;
        if(y == 0) {
            return x;
        }else {
            
            return saiyaku(x, y);
        }
    }
    
    
}