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)

from fractions import gcd

def smallestCommon(a,b):
    return (a * b / gcd(a, b))

def caluclate(a, b, c, d):

    s1 = 2 if a / c < 2 else int(a / c)
    s2 = 2 if b / c < 2 else int(b / c)
    s3 = 2 if a / d < 2 else int(a / d)
    s4 = 2 if b / d < 2 else int(b / d)

    m1 = s2 - s1 + 1
    m2 = s4 - s3 + 1
    m3 = 0
    common = smallestCommon(c,d)
    commonB = common / c

    m3 = (s2 //commonB) - (s1 // commonB)

    return int(b - a + 1 - (m1 + m2 - m3))


S = input().split(" ")
A = int(S[0])
B = int(S[1])
C = int(S[2])
D = int(S[3])

result = caluclate(A,B,C,D)

print(result)