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 ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var N = Array.ConvertAll(Console.ReadLine().Split(), long.Parse);
            long A = N[0];
            long B = N[1];
            long C = N[2];
            long D = N[3];

            long[] AB = new long[B - A + 1];
            long count = 0;

            for (long i = A; i <= B; i++)
            {
                AB[i] = i;
                if (AB[i] % C == 0 && AB[i] % D == 0)
                    count++;
            }

            Console.WriteLine(count);
            



        }
    }
}