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 Python (3.4.3) (judge verdict: Wrong Answer)

numbers = input().split(' ')

a = int(numbers[0])	
b = int(numbers[1])
c = int(numbers[2])
d = int(numbers[3])

e = c * d
i = int(a / c) + 1
j = int(a / d) + 1
k = int(a / e) + 1
count = 0
while c * i < b:
	i += 1
	count += 1
while d * j < b:
	j += 1
	count += 1
while e * k < b:
	k += 1
	count -= 1
print(b - a - count + 1)