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 a=0, b=0, c=0, d=0, t=d, f=0;
  scanf("%d %d %d %d", &a, &b, &c, &d);
  int i1=d, i2=c, r=i1%i2;
  while(r!=0){
    i1=i2; i2=r; r=i1%i2;
  }
  int lcm=c*d/i2;
  int v1 = (int)b/d - (int)(a-1)/d;
  int v2 = (int)b/c - (int)(a-1)/c;
  int v3 = (int)b/lcm - (int)(a-1)/lcm;
  printf("%d\n", b-a+1-v1-v2+v3);
  return 0;
}