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 JavaScript (node.js v5.12) (judge verdict: Time Limit Exceeded)

"use strict"

const main = (input) => {
    input = input.split(" ");
    const A = Number(input[0]);
    const B = Number(input[1]);
    const C = Number(input[2]);
    const D = Number(input[3]);

    let sum = 0;
    for (let i = A; i <= B; i++) {
        if (i % C !== 0 && i % D !== 0) {
            sum += 1;
        }
    }
    console.log(sum);
};

main(require("fs").readFileSync("/dev/stdin", "utf8"));