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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
int main (){
long long a,b,c,d,i,m=1,n,k=0,as=0,bs=0;
    scanf ("%lld %lld %lld %lld",&a,&b,&c,&d);
    for (i=1;i<100000;i++){
  if (c%i==0 && d%i==0){
    m=i;
      }
  }
n=c*d/m;
  if (c==d){
  	as=a-1-((a-1)/c);
  	}
  	else{
 as=a-1-(((a-1)/c)+((a-1)/d)-((a-1)/n));}
 if (c==d){
 	bs=b-(b/c);
 	}
 	else{
 bs=b-((b/c)+(b/d)-(b/n));
 		}
 printf ("%lld",bs-as);
 return 0;
    }