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: Runtime Error)

// 配列の重複を排除する
function uniq(array) {
  return Array.from(new Set(array));
}

function Main(input) {
  var A = parseInt(input[0], 10);
  var B = parseInt(input[1], 10);
  var C = parseInt(input[2], 10);
  var D = parseInt(input[3], 10);

  var cNum = A % C !== 0 ? Math.floor(A / C) + 1 : Math.floor(A / C);
  var dNum = A % D !== 0 ? Math.floor(A / D) + 1 : Math.floor(A / D);

  var baisuu = [];

  // A~Bの範囲のCの倍数を求める
  while (C * cNum <= B) {
    baisuu.push(C * cNum);
    cNum++;
  }
  // A~Bの範囲のCの倍数を求める
  while (D * dNum <= B) {
    baisuu.push(D * dNum);
    dNum++;
  }

  // console.log(JSON.stringify(baisuu));

  var uniqArray = uniq(baisuu);
  // console.log(JSON.stringify(uniqArray));

  console.log(B - A + 1 - uniqArray.length);

}

Main(require("fs").readFileSync("/dev/stdin", "utf8").trim().split(/\n|\s/));