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 C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AtCorder_0519
{
    class Program
    {
        static void Main(string[] args)
        {
            var line2 = Console.ReadLine().Split().Select(int.Parse).ToArray();

            var A = line2[0];
            var B = line2[1];
            var C = line2[2];
            var D = line2[3];

            long cnt = 0;
            for (var i = A; i <= B; i++)
            {
                if ((i % C != 0) && (i % D != 0))
                {
                    cnt++;
                }
            }
            Console.WriteLine(cnt);
        }
    }
}