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) {
        final Scanner scanner = new Scanner(System.in);

        final long a = scanner.nextLong();
        final long b = scanner.nextLong();
        final long c = scanner.nextLong();
        final long d = scanner.nextLong();

        final long cd = c * d;

        long minValueDivByC = (a / c) * c;
        if (minValueDivByC != a) minValueDivByC += c;

        long minValueDivByD = (a / d) * d;
        if (minValueDivByD != a) minValueDivByD += d;

        long minValueDivByCD = (b / cd) * cd;
        if (minValueDivByCD != a) minValueDivByCD += cd;


        long maxValueDivByC = (b / c) * c;
        if (maxValueDivByC != b) maxValueDivByC -= c;

        long maxValueDivByD = (b / d) * d;
        if (maxValueDivByD != b) maxValueDivByD -= d;

        long maxValueDivByCD = (b / cd) * cd;
        if (maxValueDivByCD != b) maxValueDivByCD -= d;



        long sum = (maxValueDivByC - minValueDivByC) / c + 1L;
        sum += (maxValueDivByD - minValueDivByD) / d + 1L;
        sum -= (maxValueDivByCD - minValueDivByCD) / cd + 1L;

        System.out.println(b - a - sum + 1);
    }
}