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>
using namespace std;
int gcd(int,int);
int main()
{long long int a,b,c,d,tol,number1,number2,number3,lcm;
 while(cin>>a>>b>>c>>d)
 {
 lcm=c*d/gcd(c,d);
 tol=b-a+1;
 number1=b/d-(a-1)/d;
 number2=b/c-(a-1)/c;
 number3=b/lcm-(a-1)/lcm;
 int ans=tol-number1-number2+number3;
 cout<<ans<<endl;
 }
 return 0;
}
int gcd(int a,int b)
{while(b!=0)
{int c=a%b;
 a=b;
 b=c;
}
return a;
}