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;

	class Program
	{
		static void Main(string[] args)
		{
			string[] values = Console.ReadLine().Split(' ');
			int a = int.Parse(values[0]);
			int b = int.Parse(values[1]);
			int c = int.Parse(values[2]);
			int d = int.Parse(values[3]);
			int count = 0;
			for (int i = a; i <= b; i++)
			{
				if (i % c != 0 && i % d != 0)
				{
					count++;
				}
			}
			Console.WriteLine(count.ToString());
	}
}