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) {
	int a, b, c, d,e,f,g,h,i,j,k;
	scanf("%d", &a);
	scanf("%d", &b);
	scanf("%d", &c);
	scanf("%d", &d);
	e = a / c;
	f = a / d;
	g = b / c;
	h = b / d;
	i = a / (c*d);
	j = b / (c*d);
	k = a - b - e - f + g + h + i - j -1;
	printf("%d", k);
	return 0;
}