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: Time Limit Exceeded)

#include <stdio.h>

int main(void) {
	long int A, B;
	int C, D;
	scanf("%ld%ld%d%d", &A, &B, &C, &D);
	int a = B - A + 1;
	int count = 0;
	for (int i = 0; i <=B-A;i++) {
		if ((A + i) % C == 0) {
			count++;
		}
		else if ((A + i) % D == 0) {
			count++;
		}
		else if (((A + i) % C == 0) && ((A + i) % D == 0)) {
			count--;
		}
	}

	printf("%d",  a-count);


	return 0;

}