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 n,m,k,i,j,l,t,v,cnt=0;
	while(~scanf("%lld%lld%lld%lld",&n,&m,&k,&l)){
		if(n%k==0){
			t=n/k;
		}else{
			t=n/k+1;
		}if(n%l==0){
			v=n/l;
		}else{
			v=n/l+1;
		}
		for(i=t*k,j=v*l;i<=m&&j<=m;j+=l,i+=k){
			if(i<=m){
				cnt++;
			}if(j<=m){
				cnt++;
			}
		}
		printf("%lld\n",m-n+1-cnt);
		cnt=0;
	}
}