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: Wrong Answer)

'use strict';
function main(input) {
  const args = input.split(' '),
        A = parseInt(args[0]),
        B = parseInt(args[1]),
        C = parseInt(args[2]),
        D = parseInt(args[3]);
  let cnt = 0;
  for (let i = A; i != B; ++i) {
    if (i % C !== 0 && i % D !== 0) {
      ++cnt;
    }
  }
  console.log(cnt);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));