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(void){
  long long int a,b,c,d;
  scanf("%lld%lld%lld%lld",&a,&b,&c,&d);
  long long int cnt=0;
  long long int i=0;
  for(i=a;i<=b;i++){
    if((i%c==0)||(i%d==0)){
      i++;
    }
    if(i % c !=0){
      if(i % d !=0){
        cnt++;
      }
    }
  }
  printf("%lld",cnt);
  return 0;
}