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++14 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include<stdio.h>
int main(){
	long long a,b,c,d,t=0,n;
	scanf("%lld%lld%lld%lld",&a,&b,&c,&d);
	if(a>b)
	{
		n=a;
		a=b;
		b=a;
	}
	t=b-a+1-b/c-a/c+b/d-a/d;
	printf("%lld",t);
	return 0;
}