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)

L = list(map(int, input().split()))

c = L[1] - L[0] + 1
# Cで割れる
d = L[1] // L[2] - (L[0] - 1) // L[2]
# Dで割れる
e = L[1] // L[3] - (L[0] - 1) // L[3]
# CでもDでも割れる
f = L[1] // L[2] * L[0] // L[1] // L[2] - ((L[0] - 1) // L[2] + 1) * L[0] // L[1] // L[2]
c = c - d - e + f + 1
print(c)