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)

import fractions
a,b,c,d = map(int,input().split())
num = b-a+1
ac = int((a-1)/c)
ad = int((a-1)/d)
bc = int(b/c)
bd = int(b/d)
e = c*d//(fractions.gcd(c,d))
a = int(a/e)
b = int(b/e)
c = bc-ac
d = bd-ad
e = b-a
print(num-(c+d-e))