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(){
  int count = 0;
  unsigned int a,b,c,d,i,tmp,r,syou,multi;
  if(scanf("%u %u %u %u",&a,&b,&c,&d) == 1);
  multi = c * d;
  if(c < d){
    tmp = c;
    c = d;
    d = tmp;
  }
  r = c % d;
  while(r != 0){
    c = d;
    d = r;
    r = c % d;
  }
  syou =  multi / d;
  
  count = b-a+1 - (b/c + b/d - b/syou) + (a/c + a/d - a/syou);
  printf("%d",count);
}