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.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		long A = scn.nextLong();
		long B = scn.nextLong();
		long C = scn.nextLong();
		long D = scn.nextLong();
		long ans = B-A+1;
		ans -= (B-A-(C-((A%C)==0?C:A%C)))/C + 1;
		ans -= (B-A-(D-((A%D)==0?D:A%D)))/D + 1;
		ans += (B-A-(C*D-((A%(C*D))==0?C*D:A%(C*D))))/(C*D) + 1;
		System.out.println(ans);
	}

}