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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<iostream>
#include<string>
#include<cmath>
#include<algorithm>
#define ll long long
using namespace std;
int gcd(int a, int b){
	if (a%b==0){
		return b;
	}
	else {
		gcd(b, a%b);
	}
	
}
int main(){
	ll A, B, C, D,ans=0;
	cin >> A >> B >> C >> D;
	int ss = (C*D) / gcd(C,D);
	A--;
	int hkytB = B / ss,hkytA=(A)/ss;

	cin >> A >>  B >> C >> D;
	ans = (B - (B / C) - (B / D) + hkytB) - (A - (A / C) - (A / D) + hkytA);
	cout << ans << endl;
	return 0;
}