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 = input().strip().split(" ")
A = int(A)
B = int(B)
C = int(C)
D = int(D)

div1 = A // C
div2 = A // D
div3 = (B-1) // C
div4 = (B-1) // D

X = C*D // int(fractions.gcd(C,D))
div5 = A // X
div6 = B // X

del_nums = (div3 + div4 - div6) - (div1 + div2 - div5)
result = B - A - del_nums
print(result)