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 (2.7.6) (judge verdict: Runtime Error)

import copy
import math

inp = str(input())
# inp = "314159265358979323 846264338327950288 419716939 937510582"
inp = inp.split(" ")
a = int(inp[0])
b = int(inp[1])
c = int(inp[2])
d = int(inp[3])

h = c * d / math.gcd(c, d)
e = int(b / c) - int((a-1) / c)
f = int(b / d) - int((a-1) / d)
g = int(b / h) - int((a-1) / h)

print((b-a+1)-(e+f-g))