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 int a,b;
    int c,d,e,f,r=1,i,n,cd,count1=0,count2=0,count3=0;
    scanf("%ld %ld %d %d",&a,&b,&c,&d);
    e=c;
    f=d;
    while(r!=0){
        r = e % f;
        e = f;
        f = r;
    }
    cd=(c*d)/e;
    if(a%c==0){
        count1=b/c-a/c+1;
    }else{
        count1=b/c-a/c;
    }
    if(a%d==0){
        count2=b/d-a/d+1;
    }else{
        count2=b/d-a/d;
    }
    if(a%cd==0){
        count3=b/cd-a/cd+1;
    }else{
        count3=b/cd-a/cd;
    }
    //printf("%d %d %d",count1,count2,count3);
    printf("%ld",b-a+1-count1-count2+count3);
    return 0;
}