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)

a, b, c, d = map(int, input().split())
 
count = b - a
def baisuu(n):
    i1 = (a // n )
    i2 = (b // n)
    return int(i2 - i1 + bool(a % n or b % n))
 
def gcd(x1, x2):
    x = x1 * x2
    r = x2 % x1
    while r != 0:
        x2 = x1
        x1 = r
        r = x2 % x1