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 <cstdio>
#include <map>
#include <algorithm>
#include <vector>
#include <string>
#include <utility>
#include <queue>
#define INF 1e16
#define rep(i,n) for(int i=0;i<n;i++)
#define NO cout<<"NO"<<endl;
#define YES cout << "YES"<<endl;
#define No cout << "No"<<endl;
#define Yes cout << "Yes"<<endl;
#define all(a) a.begin(),a.end()
#define P pair<int,int>

//(int)'a'は97 (int)'A'は65 (int)'1'は49
//おまじない

using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

const ll maxn=100000;

int main(){
    
    ll a,b,c,d;
    cin >> a>>b>>c>>d;
    ll range = b-a+1;
    
    cout << range-range/c-range/d+range/c/d<<endl;
    
    
    
    return 0;
}