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: Runtime Error)

import math
A,B,C,D=map(int,input().split())


def lcm(x, y):
    return (x * y) // math.gcd(x, y)


#print(len([x for x in range(A,B) if x%2!=0 and x%3!=0]))

size=B

cd=lcm(C,D)
allC=size//C
allD=size//D
allcd=size//cd
ALL=size-(allC+allD-allcd)

size=A-1
cd=lcm(C,D)
pC=size//C
pD=size//D
pcd=size//cd
P=size-(pC+pD-pcd)

print(ALL-P)