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 Java (OpenJDK 11.0.6) (judge verdict: Time Limit Exceeded)

import java.util.*;
import java.io.*;
public class Main{
        public static void main(String[] args){
                Scanner sc = new Scanner(System.in);
                PrintWriter ou = new PrintWriter(System.out);
                long a = Long.parseLong(sc.next());
                long b = Long.parseLong(sc.next());
                int c = Integer.parseInt(sc.next());
                int d = Integer.parseInt(sc.next());
                sc.close();
                int cc = c;
                int dd = d;
                long s = 1;
                for(int i = 2 ; i <= c ; i++){
                        if(c % i == 0 && d % i == 0){
                                s *= i;
                                c /= i;
                                d /= i;
                                i--;
                        }
                }
                a--;
                s *= c * (long)d;
                long yono = b - a - b / cc + a / cc - b / dd + a / dd + b / s - a / s;
                ou.print(yono + "\n");
                ou.flush();
        }
}